Taste the rainbow! Build the rainbow!

Im not sure how the blocks are coded but I will leave that to the smart people.
My suggestion is that you can have a several grey textured blocks to build with but you are allowed to chose a rgb color that will tint the block.

I know this could get intense with memory usage that shy i would suggest when you create a new color it would get intense for the game to handle wich is why i think it should create a new texture file(or however its done) so it acts like any other building color.

I am not very knowledgeable in coding so this is probably a bad suggestion