Yeah I thought about this. The thing is, every time you try and over-categorise something (not just icons, could be code, could be anything) you end up stalled and with a bunch of things you can’t categorise, or a bunch of things in the same category, or lots of generalised categories, or lots of very specific categories.
In the end, categorisation is hard, and a lot of the icons don’t benefit significantly from being specific categorised colours. It isn’t a primary concern, especially because shape belies those connections, as well as proximity, already.
For instance, say we try and categorise rendering into greys. The first three icons all become the same colour and then there’s less benefit.
Or, what if we decide grey for rendering things, cyan for scene, orange for object, green for data, blue for modifiers, red for materials and textures, yellow for effects, and… We’re out of significant colours for physics.
The place that benefits from strict categorisation is the outliner, where those categories are much easier to discern, but are also broader and fewer.
So in the end, what I’ve been going for is similar to what I see when I look at the 2.79 icons, merged with the new ones.
Add an outline, so the icons work for any theme.
Add a splash of colour, try and be reasonably consistent, but don’t fret about it because in the end it’ll never be perfect.
Keep the icons bright, but not hugely saturated. This way they blend in with white icons and the rainbow effect is avoided.
Don’t colour every icon needlessly, which can be done if the colours are made to blend nicely with the white icons. We’re aiming for ‘signposts’, not rainbows.
Colours are also reasonably easy to change, it’s the outlines that are taking time, since most icons have to be shrunk slightly to accommodate them. So I am more concerned with what colour goes where later.
I didn’t intend to have these discussions in Jendrzych’s thread, once I have more progress I’ll open another one. Apologies.