I recently wrote a post about matching colour. I was going to write more on that post but have decided to write a new post.
I am working on the latest on my easel and trying to match colours in a forested area in the far background. I spent some time trying to decide what colours to use. I began painting and noticed that the colours had changed. I painted a little more and noticed that the colours had changed again — a bit, so I went through the whole colour matching process again.
Had I been painting in plain air this would be more understandable since colours change during different hours of the day, but I was using a printout so the colour wasn’t changing; my perception was. I remember one of my instructors telling me to never completely paint over a colour because the first colour likely wasn’t wrong. I believe our perceptions of colour change based on surrounding colours so trying to match a colour will never work the first time because the surrounding colours will always alter our perception. This has been backed up with research over the years. I’ve also read that our perception of colour changes depending on our mood, but I’m going to stick with a more physical reason for the moment. In graphic design it is common to work in a room with the lights off, windows covered and the entire room painted medium grey (medium grey is darker than you think). I remember one of my instructors telling me to always use an under-colour wash because the canvas white is so blindingly white. You would think that a white canvas would make it easy to match colours but the opposite is true.
I’ve always used a wash on my painting surface because I believe it shows through or adjusts the final look of the painting; so, a warm wash should make the painting look warmer. To be clear, the colour wash adjusts my perception of the colour. There may be some ‘show through’ because many paint colours are somewhat transparent but I’m going to stick with the idea that it’s my perception that is changing. As a result, I often use a wash that is a pretty starling colour; if I want the painting to appear warm, I use a rather brilliant yellow, red, or yellow-ocher, and if the painting is going to be cool, then ultramarine blue makes sense. These are usually light washes rather than highly saturated colours but I don’t see a problem using highly saturated colours other than it can make preliminary sketches difficult to see.