Digital Painting 101: Mixing Paint

Digital Painting 101: Mixing Paint

As one colour approaches another there’s always a blended transition. Even if your subject is painted a single colour it will have lighter and darker areas. Because colour is affected by light and form, it has a huge amount of variation. Even a sheet of white paper seen on a cloudy day contains a gradation subtle colours.

So what does this mean for you?

It means that you’re going to be doing a lot of blending. As a general rule, Photoshop does not do a great job of imitating the way real paint blends. If you have traditional painting experience, be prepared to learn some techniques that will seem quite foreign. Don’t worry – Photoshop will do a great job blending colours, but the method is uniquely digital.

One colour into another

In this simple example you can see two primary colours: highlight and shadow. Where the form turns away from the light there’s a colour transition.

On-Screen Mixing with the brush tool


The secret to painting a colour transition lies in the brush tool + eyedropper. As you learned in lesson #2 the Alt key will temporarily call up the eyedropper while the brush tool is active. ‘Sampling’ in this way gives you an incredible power that traditional painters would kill for. To create a middle mixture between two colours use the following steps:

  1. Sample colour A and paint a swatch of it in the middle.
  2. Sample colour B and paint it lightly over top of the middle swatch.
  3. To paint with this middle mixture, sample it with the alt button!

This process is known as ‘on-screen mixing’ and is quintessential for digital painting. It’s not similar to painting with oils, but will quickly feel intuitive. When using this on-screen mixing technique, you’ll experience two major bonuses to your workflow:

  • Save tons of time. Every time you avoid opening the colour picker window time is saved. To maximise this effect, use the eyedropper (alt) tool as much as you can.
  • Create a unified colour scheme. If you are primarily mixing on the canvas, your colours will naturally harmonise with one another through blending.

Using a ‘Mini-palette’

Traditional painters are required to pre-mix paints on their palettes before starting to work. In this way they are able to plan out a pleasing colour scheme ahead of time. Digital artists aren’t forced to do this step because there’s no physical paint involved. Even though not strictly necessary, I would ague that pre-mixing digital colours is a worthwhile endeavor.


When starting a colour painting, my first step is to create these pre-mixed colours on what I refer to as a ‘mini-palette’. It’s simply a blank layer that I title “palette” and paint small swatches on. Because it’s on a separate layer I’m able to move it around my canvas when it gets in the way, or to hide it completely with the visibility button.

The specifics of the mini-palette format are up to you. I like to keep mine small and unobtrusive. Some artists like to paint swatches of their main colours – but I like to include mixed gradations as well. Doing so gives me a pleasing colour palette because middle mixtures have a nice neutralising quality.


Mixing productively

One of my main goals when approaching Photoshop for concept art is efficiency. I’ve found the most success through a combination of on-screen mixing and sampling from a mini-palette. When both of these techniques are used, one can almost completely avoid the colour picker window – and save a ton of time.

Homework: Swatches

If you only take one thing away from this lesson it should be the power of the Alt key. What takes a traditional painter time and effort to mix is only a click away for photoshop users, so take full advantage.

The following worksheet might be a familiar sight to art school students. It’s not glamorous, but it’ll get you mixing accurately in no time. The goal is to use the principles of on-screen mixing to mimic the examples provided.

  1. Sample from squares A and B to create middle mixture C
  2. Find the middle mixture between A and C
  3. Use the same technique to mix B and C
  4. optional bonus: use the soft round brush to create smooth transitions between each colour swatch

So save a copy of this sheet, and start mixing!



  • Anyone using Gimp, you can get the ‘flow’ effect by selecting the ‘Incremental’ box in your brush properties, and turning the opacity right down (like to 5%) this gives you the 50:50 flow rate available in the above Photoshop [TM] tutorial.

Log in to comment on this story!