Short answer: most likely just the lighting.
Long answer: MT3 and DCX have a different enough surface finish that the observed colors will appear different if the same material is used. Because of this, we use slightly different material colors to achieve the same (or as close as possible) observable color between the two profiles for comparable sets. These subtle differences and surface textures will also impact how different lights reflect and interact with the sets. So, it's primarily the lighting, but there is more to the story and color is a super fascinating rabbit hole to go down if you ever are so inclined.