I have tried many things to get my fondant a purple colour. Wilton paste turns a sickly grey-blue colour, colour dust makes it taste really weird. Mixing red and blue colouring together is unreliable and makes colours that are hard to recreate.

How can I get a nice purple fondant colour? I'm at a loss.

I need a purple also... I'm very close to going to Michaels and purchasing some already colored fondant... as much as I hate doing it.

It may depend on the brand of fondant you are using....at least one brand of white fondant has a whitening agent in it which interacts with some of the gel colorants. I had a lovely robin's egg blue result from using the violet get in white fondant; the manufacturer told me that the ivory fondant is to be used when colouring. There was nothing about this on either label though.....
I ended up using rolled buttercream for the pink and purple parts of the cake, and the fondant for green and yellow (it was a girl's first birthday cake).

Thanks LABRAT! That's a great tidbit to know. It makes sense.... but they should have placed a warning on the box.

Americolor works best for me.