Caveopolis is a mod that adds many new different colored blocks 

Currently adds colored stone, cobblestone, cobblestone brick and planks

Join the discord to report bugs issues suggestions

https://discord.gg/benbenlaw

Some other stuff added:

Mossy stone

Moss balls

bright stone and bright shards (can be used to make stone torches)

stone crafting table

mixed stone ingots

Can be used in any modpack