Everyone knows that pink angora comes from pink angora rabbits. Haven't you seen the remake of charlie and the chocolate factory?
Seriously though, angora is an animal fiber so it can be dyed with the same acid dyes used to dye wool. Different protein fibers, while they all can be dyed with acid dye, all take dye at different rates so with a wool angora blend yarn, one fiber might be a deeper shade than the other. Depending on how fibers in the yarn are blended, this could mean a heathered look or a spiral look.
I remember reading on the paula burch site that angora supposedly takes acid dye lighter than wool does.
Paula doesn't spin or knit but she is still incredibly knowledgeable about all types of dye, including acid dyes. Her web site is the first place I go when I have a dye related question.
I have yet to dye angora but I do have a few grams of angora fiber hanging around as leftover from a project, and I have tons of wool, so wait a day and I'll dye up a bit of wool and angora in the same bath and post the results.
Search results for "angora" on paula burch's site: