I sheared a grey sheep and instead on having the grey head it when to the white version but re gained its color when it regrew its wool
Linked issues
duplicates 1
Comments 2
Hi there!
This looks like a duplicate of MC-1823. This is an intentional feature, and you shouldn't expect it to be patched as a bug. You can suggest a change to this on the feedback website at https://feedback.minecraft.net/hc/en-us.
Most Likely a feature request. They don't have colored textures for sheared sheep.