It's doable, but, on the modelling side, it would require editing all spoiler models to remake the texturing on them, and that's a painful process. On the scripting side, it would require to create another "thing" where to place color into and add it to the UI, as well with a switch to make the model change UVs (or change the whole model), so you can place vinyls on it separately or not at your will (which would require yet another new UI element)... At least this is what I'm guessing.
I would (purely) speculate that they might do it, but not soon at all, for being such a lengthy process for such a small feature.