If you want to paint it purple, fine
If you want to make it glow with UV, fine
Once you have paid for, and purchased a product, you may use it in any way you see fit. This is a right of the purchaser, they have paid for the right to dispose of, or alter the item in any way they see fit. Since this right is implicit in the financial transaction of purchacing an item, it is axiomatic that it cannot be removed by legislation. Therefore, the DMCA in this application is not valid and cannot be legally applied.
Either fight the power, or knuckle under. Your choice.