I love tailwind. I would like the addition for perceptual color palette. I do it by hand with HSLuv and I redefine the colors, but having a built in way to build light on ark and dark on light contrast that look good regardless of hue would be cool.
My understanding is that that's a non-trivial problem. You'd likely need some sort of AI system to do it, since the perception of colour isn't something that can be simply modelled.
