[Suggestion] Use blockstates to get light color

[paulevsGitch]

Hi, it will be a great addition if it will be possible to define custom colors for different blockstates of the same block. As I can see color request uses blockstates, but color registration use only blocks (and that's actually limits possible colors for blocks). Looks like it will require some small changes, but as a result it will allow to add blocks with more complex light. Adding basic non-json API will help with this too (for example if there will be an API that allows return color based on blockstate + position this will allow modders to use block color providers as a source of color too)