The default colors of M3 and V3 don't use textures, you have to add one with an image node, like the tutorial you linked to has it set up.

And any texture sets you have for the character, which are usually in the Pose folder and called a MAT file will automatically do this for then entire character.

________________________________________________________________

If you're joking that's just cruel, but if you're being sarcastic, that's even worse.