I think the best option would be to allow customization of how the cards look. Scan symbols off a set of cards for the visually impaired (The large characters with clearly named cards and large suit symbols). This would allow anyone with poor eyesight who needs it to use cards that are significantly easier to read. The major problem with this is that the hand would need to appear more spread out, but I'm sure something could be done. As for suit symbols for the rest of us, I like Green, Orange, Red, Blue although I think the blue should be closer to black for the spade. The orange should perhaps be slightly darker but still clearly orange and not red. The club should remain a reasonably dark green. But this is just my opinion, comments are welcome.