• Colored Warp-Plates: Give the Warp Plate a dye slot. The runes on the plate get the color of the dye inserted.
• Named Shards: If the Shard has a name (via Anvil) display the name hovering over the plate. If the plate has a color maybe even in the color of the plate. (See Screenshot-Mockup)
  

Colors are going to be reserved for sharestones to clearly differentiate between the "activatable" network (regular waystones, white) and network-wide sharestones (and colored portstones). #814

Since warp plates fall into neither, the decorational purpose of coloring them would not be worth the potential confusion / inconsistency it would create.

As far as I know, displaying a nameplate is no longer easily possible since Minecraft 1.14, and this isn't really something I would want to have lots of code for in the mod. If Minecraft re-adds a native way to add nameplates in world it would be something to consider.