Originally caused by6514bb05eaMore cases where the active/default color attributes were not set correctly: [1] Using the old Python vertex_colors API (vertex_colors.new) [2] OBJ importer [3] Collada importer [4] Data Transfer layout (both standalone operator and "Generate Data Layers" from the modifier) Similar to101d04f41f. Brought over from https://archive.blender.org/developer/D16977, see discussion there why some of the code for data transfer is not for the genereal attribute API. Pull Request #105020