This time it's not my work - but someone implementing one of *my* feature requests!
When I worked on porting GIMP to the v2 MyPaint Brush API, I didn't implement the optional Spectral Blending feature. If turned on, the blending mimicks "real world" pigment mixing - so for instance, painting yellow on blue creates a green color around the edges instead of grey-ish yellow.
I posted a feature request, and a new contributor took me up on it. See the video for a quick demo of how it works!
Krita's KPL palettes for a while, ever since we added export support in GIMP 3.2.


