A Simple Guide to Digital Colour

Using an older ink drawing of an octopus, I’m going to be running through the basics of how to apply digital colour to an image in an easy way for beginners. I’m not including any advanced techniques just the basics of colouring a black and white drawing. It doesn’t matter if this drawing was done traditionally and scanned in or of it was done digitally.

In terms of software applications, I’m using a mixture of Photoshop 6.0 and the Android app Autodesk Sketchbook. However the tools and basic techniques I’ll use here should be available in almost all digital art applications and the names of these tools are fairly consistent across all platforms too.

Below is the image I’m going to add colour to. It’s one of the black and white ink drawings of an octopus I made a month or so ago.

I used a camera to photograph my traditional ink drawing and then loaded it up into the computer. Sometimes I scan a drawing in too. Once I had it uploaded I cropped the drawing and then transferred it to my tablet so I could load it into Autodesk Sketchbook. Below, you can see it loaded up in the Sketchbook program.

Using blending modes to see your line art over the top of your colour

The first issue beginners get when adding colour to a black and white drawing is how to colour the picture without painting over the drawing. To do this we use the layer blending modes which are present in almost all digital art applications.

To do this in Sketchbook I clicked the layer with my line art on it…

Then I clicked the part of the menu which was about blending modes…

This brought up a list of layer blending options. Then I chose “Multiply”, like this…

Once I’d done that any colour I put in the layer below the octopus would show through the line art. I could then colour the drawing without touching the line work…

Masking with flats

The next thing I do for most digital drawings is to create what is called a flat layer. This is where you draw flat colours (just plain 100% colour) onto a new layer of your digital drawing. You can later use these flat colours to quickly select different areas. In a more complex design you might have many different colours and tones of flats to set up so you can colour lots of different parts of your drawing easily and seperately, but in this design I just want to be able to distinguish between the octopus and her background, so I just drew some flat colour over my octopus like this…

If you look at the flat colour I added without the line work showing it looks like this – below. (This was my first pass. You can see how I needed to tidy it up and make it much tighter.)

Once the flat layer was done I pulled it out of the way to the bottom of my set of layers as it was really just a tool to help me quickly select things. It wasn’t ever going to be a layer which would appear in my final image. In many ways it’s exactly the same as an air-brush artist cutting out a masking sheet to allow them to colour one bit of the painting and not another.

Colouring using my flats

Once I’d completed this flat layer I could then easily select my octopus using what is usually called the magic wand tool. This tool will select all of a particular colour range or tonal range on your picture. Here I used just one single flat colour with no variation in it. The magic wand tool finds this really easy to select. So I clicked on my flats layer and clicked on the octopus and the magic wand tool selected the octopus for me.

With the octopus shape selected I could then colour the octopus using the air brush tool without going over the edge of the animal. In this way I could apply a range of colours in a gradient like this really easily…

Colouring using layers

Next I wanted to put in some background. For this I made a new layer below my octopus ink layer, and my octopus colour layer and then painted over it again using the spray paint tool. Because it’s a background and I want my octopus to “pop” off the page I used, on average, a lower saturation and darker tone for this. Our eyes are drawn to things which are more saturated and have more contrast. So making my octopus lighter than her background and more saturated really helped.

I thought this looked a bit dull though, so I used a spotted brush to add some texture to the background as if rolling breakers were crashing above our scene causing foam to appear in the water. I put this these textural marks on a seperate layer…

Once this was done I used the pen tool to draw in some colour for some of the details, like the octopuses eye and the lumps on her mantle. I used another new layer to do this. By keeping my layers seperate I could then alter things later really easily if I wanted to make changes. As it happened on in this picture I later realised that I hadn’t coloured my octopuses suckers. I could then go back and add the sucker colour to this layer with all of the other details on it. Because I kept it seperate if I made a mistake while painting this addition I could easily erase and refine it.

Specular highlights and other “wet” effects

My next job was quite subtle. I wanted to give the viewer the feeling that the octopus was wet. So I added what are called “specular highlights“. These are sharp bright white patches where light is directly reflected off of the octopuses wet body. I’ve put a big one on her mantle and some thinner linear highlights on her arms. You wouldn’t actually see this on an octopus under the water since the reflection happens because of the air-water interface on wet surfaces, but giving my viewers the right impression helps draw them into the illusion of a wet subject.

Then, to encourage the viewer to see the background as water too I also added some circles for bubbles. Now in a natural environment, without a diver present, there aren’t always any bubbles to be seen, but I think they help sell the image so I put them in anyway. Finally I made my correction to the suckers as well to add more interest to the picture.

Final adjustments

My final job was to bring the image into Photoshop (or I could have used another digital art package, like Clip Studio Paint or Affinity Photo) and adjust my colours and levels. I do this in Photoshop because the Photoshop tools for this are much more accurate and effective than the free app Autodesk Sketchbook. Here I wanted to make sure that I’d got some good bright highlights, some nice dark shadows and colours that worked well for the feel I was going for.

Colour modes

If I were going to print the image I would then change the “mode” of the picture from RGB, which I normally work in, to CMYK, which adjusts the picture colours for printing. Since this image is for here on the web, RGB will be perfect, so I didn’t change to CMYK.

If you do want to print a colour image all you have to do is set the image mode to CMYK. Sometimes there are several CMYK options to choose from and which one you use depends on your printer. But any CMYK mode will help your printer print an image with better colour.

What happens when you switch to CMYK mode is that the image’s colour will seem to change a bit. What the computer is doing is showing you how the image will look when you print. If you don’t like the changes it has made then you can adjust the colour hue (red, yellow green blue etc) and the saturation to get the image how you would like it. Don’t be afraid to play around with the colour to see what it can do and what you prefer. Just use the undo button if you don’t like your changes.

(Managing colour is actually a very complex issue which also involves the colour characteristics of your computer monitor as well as your printer. Humans also see colours differently from person to person. I’m not going to go into any detail on this topic here as it’s quite advanced and involves understanding colour spaces and how to manage them. The only concept you need from here is that it helps to use CMYK for printing and RGB for the web.)

Here is my final RGB coloured image…

That’s all for now. I hope this was helpful.

If anyone has a go at using this guide and makes some artwork I would absolutely love to see it! You can always link it in the comments if you decided to have a go. I would also be happy to include a link to your artwork here on this post if you would like to share it like that.


An Easy Digital Colouring Process

This week I worked on a number of smaller images in my sketchbook and started a bigger project.  The smaller images were in ink and pencil…


[Pencil on paper]



[Ink on paper]


[Ink on paper]

(NB:  The Drawing is my own but the character ‘Strontium Dog’  (aka Johnny Alpha) belongs to 2000AD (Rebellion) and the art style I used was my own version of Carlos Ezquerra’s brilliant work.)

Then I coloured them digitally.  I thought it would be fun to go through the basic colouring process I use with the gecko picture as an example.

(1) I start by scanning in the art work and cleaning any scanning artifacts (I always get one which is irritating).  I also do a general clean up of the image and adjust the curves and levels if it’s needed.  I usually do this bit in photoshop.

(2) Then I save the cleaned image and open it in Manga Studio 5.

(3) My next big job is to put in the ‘flat colour’.  Basically this process involves colouring every pixel of the drawing in flat solid colour with no anti-aliasing, shading or anything else – just flat blobs of colour right up next to each other.  I tend to use colours similar to those I want to use in the final product but you don’t have to.

So here, I’m putting in the flat colour for the first few leaves…

To combine the colour with the line art like this I put the line art in the top layer and set that layer to ‘multiply’.  Then I paint my flat colour in the layer below.

Here’s a bit more flatting done…

(Here you can see I’ve accidentally painted the flower properly with final colours in the flatting layer.  I could have wiped it all out and made it white but I knew there wasn’t much I wanted to do with that part of the picture so I left it.)

Generally I paint the flats using the polygon selector with anti-aliasing off so I get a clear division of one colour or the other with nothing in between.  Once I’ve selected my area I just fill it with solid colour.

Finally when all the flat colour is done it looks like this (without the linework on top of it)…


So with the linework we’ve now got to this…


I really love flatting images, I find it repetative but nice and it makes me feel relaxed.

(4) Next I complete the detailed colour and shading for each flat area.  This is where the real digital painting starts and I find in a lot of ways I can paint in my PC just like I paint on a canvas.  I can’t always get the same effects digitally but I do have the advantage of the back button which will undo my last few changes – I wish I had that on paper sometimes!

Here’s the painting done for the leaves but not yet the gecko…

And here’s the desktop with the gecko painted fully too…


(5) Finally I put on any borders I need and save the fullsize image, then reduce the size for the web and it’s ready to go.

Here are my final coloured pictures…



Fishing, a Baby and Some Rocks…

This week I didn’t have too much time for art (still recovering from my cold) but I did manage some simple stuff.

The first was a sketch of some rocks with water running over and around them.  I found it really challenging.  I would like to paint a watercolour of this and my idea was to try to do a value sketch so I could see where the complicated light and shadows are in such a situation.

Here’s the sketch, such as it is…



Then I went on to draw a relaxing fishing scene.  I got the idea for this painting from some work I’m doing with the children in school.  We’re planning to make sillouette pictures of the Great Fire of London.  I was thinking about that and then wondered if I could make a painting using sillouettes of fishing – my favourite relaxing passtime.  (I haven’t fished since the summer but if it’s not too cold and if we’re both well, my son and I might go out this weekend.)

In terms of planning this one was easy.  I just made a sunset coloured wash – all reds and oranges and yellows and then sketched my fishing scene over the top.

Initially I was going to ink my scene onto the paper over the wash but my pens didn’t take kindly to the paint and I didn’t want to ruin them so I painted the black stuff using gouache black.  At the end I put in some highlights using yellow mixed with some gouache white.  Here are the results…


The last thing I worked on this week was a Madonna and Child sketch in my sketchbook.  I got the idea from a Christmas card which somehow escaped my post Christmas clear-out.

I drew it in pencil and then inked it using a watersoluble multiliner.  Then I used water to move some of the ink to add some tone…


I like how most of this turned out, but you can see some errors.  For instance I used the water soluble pen in the baby’s hair to give it some texture when I should have used a water resistant one so that the ink there didn’t move when I toned the hair.  Oh well, as our head teacher has on her door…

“If you want to succeed, double your failure rate!”

PS:  Just to see what it was like I also coloured this picture digitally…


I used the Manga Studio watercolour brushes to add some texture.

Days 29 to 31 – Animal Managery

I sketched out some animals in my notebook and used their shapes to kind of fit close together (ish).  Here is my line work:


Then I shaded them with pencil..



I really liked this effect – with an ink outline and the shading in pencil.

For ages now I’ve been looking for a way to illustrate in a comic style which I like and am happy with.  I’ve been playing around with different styles for years now.  However,   I just spent a few hours colouring the above  ‘Animal Managery’ drawing .  I did this in Photoshop and used a cell shading style with a mid, light and dark version of each local colour.  I did it straight over the top of the pencil and ink drawing – setting the drawing layer to multiply.

Here’s the result…


I think I’ve stumbled onto a style which I finally really like.  I’m going to follow up on this!  🙂


Digital Painting #4 – Using ‘flats’ and Vector Drawing

Today I’m going to review how and when I use something called ‘flats’ to help colour and shade digital art easily and how that fits perfectly with using the photoshop pen-tool to draw vector curves and paths .  I used to use flats all the time because they allow me to accurately control each individual part of the picture when I’m doing the final colouring and shading.  The same is true of the pen tool – the level of control this tool gives the artist is amazing.    I use both of them much less now – really just for tricky parts of an image because, while they give me good control which is fast to use, they make the final image too tight and clean.  I want a loose feel to my digital art.  It’s just a personal choice.  That said, using flats and the pen-tool is a technique I have found extremely useful at times and can produce some really excellent artwork.

But what are flats?

Well flats are sections of your picture which you can easily select and work on individually.  This is done by going over your picture and seperating each part you want to work on seperately by colouring it in a different colour.  These don’t have to be colours you’re going to use in the end product, they just need to be different from each other.  In a way flatting out a picture is just like making a mask for each part of the image – just like you would if you were using an airbrush to paint in a more traditional way.

(If you still need more info on this try this excellent tutorial: Farlow Studios Tutorial on Flats

Here’s a very simple example I drew a year or so ago using Photoshop 6:

This is my original sketch of a woman wearing a bikini:

1_OriginalSketchSo the first thing I did, after scanning the sketch into my machine, was to draw my line art using the Photoshop Pen Tool.  This tool is amazing because you can draw completely accurately anything you want, but it takes a bit of practice.  Instead of drawing a line you kind of map it out using the controls of the tool.  It is quite complicated but I found it well worth learning because it is SO powerful once you get to know it.  It’s one of the few things I would import an image into Photoshop for rather than sticking exclusively to Manga Studio.  Here is a great guide on how to use the tool:

Falling Knowledge Pen Tool Tutorial – You Tube

So here’s my pen-tool line-art:


Although you can see this image as black ink on a white background, the pen lines are actually drawn on a transparent layer in my art software (Photoshop 6) so that I can put colours etc. in a layer below and still see my pen lines.

Now in this picture I only have two basic areas – her body and her bikini.  There are two parts to the bikini but they are seperated by by lot of space so I can afford to use the same colour for both parts with out being at risk from accidentally colouring or shading one part while I’m working on the other.  While I don’t have to use any particular colour for this I decided here to use something like my final colours to save a bit of time.

So this is what my flats look like:


Notice there are no gaps between colours.

So seeing these flats with the pen lines showing looks like this:


Then I can shade and colour her skin and her bikini seperately and easily.  The following image includes the skin shading and highlights but the bikini is still plain:


And this next image is with the Bikini coloured and shaded too which finishes of the picture:


I’m not really sure what professional digital artists do – use flats and the pen tool always, sometimes or never?   Maybe it depends on what they’re doing and the final effect they’re trying to acheive?  If you are a professional digital artist I would love to know what you preference is with respect to using flats and vector lines in your artwork?     🙂

For me, I think I use them when I feel I need to, or if I was asked to do it that way for a particular project.  The only bad thing about both flats and the pen tool is the lack of being spontaneous and natural in your drawing and colouring.  These methods tighten up work and make it look kind of professional but they also somehow seem to suck the life out of it if you’re not careful.  Generally nowadays I prefer to draw and colour directly wherever I can.

(All Images unless otherwise explicitly stated are © Jo Fox, 2015)