as far as basic line dyes, don't waste your time...
best results for colorful dyes are gonna be on white Star or ESP
also milky white or transparent z, champ, opto, etc. works well
it's better to use a new premium disc but don't be afraid to get down with other lighter colored discs and ones that are slightly used.
white Pro also takes colors well for me. but don't count on it maintaining any sharp detail/fine lines for any length of time, it'll get fuzzy after a while, whereas the premium plastic's dyes will sometimes last a lil longer.
Elite X doesn't take colors well for me at all. even letting it soak in for a week, the spin dyes always start out looking faded... it feels like a wasted effort seeing your precious colors just wash off under the sink afterwards