You can paint them with plastic paint like Sonax kunststoff schwarz.
There's no need for exchange for this purpose.
In my case, this paint still holds for 2 years now and seems to hold even longer till it needs another refurbish.
Just tape and clean the parts thoroughly before painting, take your time to let it dry and put 2 layers on it.
I would teach you not to use the foam pad. Instead use a damp microfiber towel for application.
They will look and hold the color the same as new ones.
Don't compare this stuff with the other silicone detailer or coating or whatever. It's a type of a more and pigmented or permanent paint.