Slate and Deepstone

During Minecraft Live, the block that made up the Deep Dark was added in Shapshot 21w07a, and the name was changed to Deepslate the next week. The original texture was almost the same as it is now, but more light blue/light gray. If this block was added as Slate, it could be used in some sort of ice cave, near the surface of snowy biomes, or in patches, like Andesite, Granite, Diorite, and now Tuff. A new block called Deepstone could be added to generate like those Tuff in the Deepslate layer, to give more "color" to those big underground caves. It could be like a dark version of stone, but it is almost tinted a certain color to give more contrast to those big areas. It could also be a mixed color between Deepslate and Stone, making much less of a Stone to Bedrock contrast.