For painting I use kindergarten colour. Blue plus yellow makes green and red plus yellow makes orange. I keep trying different paints and pigments. Some colours in the kindergarten system (that’s my name for it) aren’t very good. Purple for instance (blue plus red) is often very muddy and unsaturated. That’s because the pigments used for blue are so inefficient. For purple I usually resort to Dioxazine purple; a modern purple pigment that I like.
This is all about experimentation. Every experiment gives me a different nuance of colour and it takes time to find the right one. Green is my latest problem. I settled on Hookers green (Bazar name). Green is easy to mix but with acrylics it’s nice to have a specific tube of a colour that you can easily revert to. I settled on Hookers green but didn’t like the way the tubes were made so I decided to change the brand. The colour was different and I needed to add blue or yellow to get the right colour. I think I’ll likely go back to mixing green from scratch when this tube is finished. This is likely a problem with modern paints because they haven’t been around for centuries to standardise the colour.