I am sporting a very cherry berry trackball..lol but I refuse to directly color the LED's for obvious reasons.. I just took my trackball out and used tape, I colored the tape my desired color then placed it over the LED then replaced the trackball. No harm no foul..lol
Someone just told me this and thought it might be of some value. The track ball is made of plastic/derlin (whatever that is) Apparently, this is a porous material and will absorb and hold dye. Walmart, Riteaid, etc sell this stuff called Rit Dye. This is what you need to change the color of the ball. This will void the warranty though I'm sure, so I'd purchase an OEM trackball also in case you run into any future problems where your BB needs to be serviced.