If you get a dragon amulet you can change the appearance of you dragon (by talking to lady Celestia), but without a dragon amulet you can only have a green baby dragon.
Yes actually, you can hack Dragon Fable IN A WAY with Cheat Engine 5.5.
I have hacked it for money but it is only the 'face value' that is hacked, you can't use the money.
here are no cheats built into the game but using certain clients like cheat engine or trainers you can hack gold, exp, health, mana and much more. for a guide to using cheat engine for dragonfable...