I received a test 8x8 RGB matrix, common anode. For common cathode, Maxim has the MAX7219 which is a serial 8-Digit driver which would work beautifully. 8 segments, 8 digits = 64 LEDs. Use three of them, one per color. Voila.
However, for common anode, they don't seem to have a serial driver. They have 8-digit drivers, but not serial. They have something called 'microprocessor compatible' (ICM7218) but it's not the same. So does anyone have a suggestion of an IC that's comparable to their MAX7219, but for common anode?
I suppose I can always tell the manufacturer to send me a different f-ing matrix. :)