There's a lot of little things that they could have / should have done to M3 to bring it even close to the standard of V3 (muscle-based mesh, unique M3 morphs rather than transplanted V3 ones, e.g. shoulder morphs, especially after they changed teh defualt .obj shape), etc., etc., ...). But in this case perhaps the (oft-dreaded) Group Tool can come to your rescue (as Daz is unlikely too). Select just the part of the forearm that needs to be a glove and make a new material. You only need to do the foream, as you can use SkinHand for the rest. Select Forearm, choose a display mode that shows the polygons, open Group Tool, create New Group, select/de-select polygons to suit, then Assign Materials. Close Group Editor and lower part of arm should be a different color, and appear in Materials under your new name. Have to do for both forearms of course.