A bit of an update on mine. It's been a little over three months since I dyed mine black with the liquid dye.

I initially had a problem with it not taking the dye very well, I had it in almost boiling water for 15 minutes and it was still purple, not black. I concentrated the dye and finally got it to black, it looked great.

It's been almost 3 months now and I've noticed the back is turning quite purple on the edges again. Really all my TP has seen is gentle pocket time, and I haven't noticed any color come off in my pockets but it's definitely coming off the case. Time for me to hit it with another dose of black tonight probably.