Which dolls specifically? Wave 1 releases typically had all different colored stands, but dolls that have been recently released typically just have black stands. (Ugh)
Here's a list of the ones I know off the top of my head, though:
Wave 1 Frankie - silver
Wave 1 Draculaura - pink
Wave 1 Ghoulia - red
Wave 1 Lagoona - silver
Wave 1 Clawdeen - salmon
Wave 1 Cleo - gold
Basic Abbey - light blue
Basic Spectra - purple
Wave 2 Frankie - blue
Wave 2 Clawdeen - purple
Wave 2 Lagoona - turquoise
Hope that helps!