Blender Git Loki

Fix T78188: Sculpt mask glitching after using sculpt vertex colors

The face sets color copy to the GPU was done outside of the loop,
probably after a merge error in a rebase.

Also, the default color was initialized using the wrong type.

Reviewed By: sergey

Maniphest Tasks: T78188

Differential Revision: https://developer.blender.org/D8106