I was worried about painting, but I did it and it was fine. Works best if you clean the glass with windex first, and even then it still takes 3 coats. A small roller (i used one 3" long) works best ... after my tank was running for a couple months I decided to paint the end next to the wall, did that with the fish corals in the tank and it was fine...
The paint will dry enough in about 30 min to do a second/third coat. I just used acrylic paint from home depot .... I must say that I'm very pleased with the results, I've used backing in the past but have always ended up with salt creep eventually, the black paint looks excellent IMO.