Thank you
I'm glad to hear that because it's actually something I've been working on recently.
For your colours to look natural you have to identify the temperature of the light you want to use. Here I'm using a yellowish light.
That means everything will take on a yellowish tint - all the blue clothing here is painted green, all the greens take on a yellowish lime green sort of colour, the reds should turn orange where hit by light (I could've done this better I think) and the far wall which probably has a natural colour of light white/yellow becomes even more yellow.
This also means I shouldn't have any primary colours other than yellow in my scene, because there is no colour mixed with yellow which = blue or red, therefore if I select any colour with a colour picker it shouldn't be pure red or blue in hue.
Starting with a coloured underpainting is a really good way to get started - in this case I grabbed this image (
www.hyoe.co.jp/blog/staff/hyoe…) and stretched it across the page and used it to sample my initial colours (you can still see some parts of it on the right side of the painting if you look closely ^^). It's a great way to get started and gives you something to compare to. If you're unsure how red should look, for example, you could just paint it lightly over the underpainting and let it blend naturally.
I have a big folder of references of different lighting conditions as well- I often study them to see how colours reacts under different lighting scenarios. Although the general premise is much like mixing paint, it's nice to have a reference to see exactly what skin colour or white cloth etc should look under certain lighting conditions.
I didn't do it here but sampling directly from photos is a great way to get a colour palette that looks natural, and you can adjust it from there once you have the colours down. I would highly recommend doing that if you can find a photo or a master painting with the sort of colours that you want. Then you have to apply your colour theory to make sure you don't break the palette when you introduce new colours.
Hope that helps! I should really take my own advice too, because a lot of what I just said I didn't apply very well, the more consistent and mathematical about it you are, the better it will look