Deep purple fondant

For darker colors it's really best to just buy it pre-colored. The pre-colored fondant purple doesn't fade.

I was trying to get a realy purple fondant as well, so I bought a couple different brands, Satin Ice purple wasn't purple enough for me, it was much closer to blue, it is pretty color I just woulnd't call it purple. I love the purple from Fondarific, it is a great deep shade.

You can add some black to purple airbrush colour to get a deeper shade. There is a top cake on a cupcake tower in my pics done this way.

HTH

Sugarflair paste colour in purple grape works really well. I usually use americolor colours, except for purple. Sugarflair's isn't a violet like i find americolor is.
However, i've never used pre-coloured fondant for purple, so i don't have anything to compare it to.

I've made purple successfully two ways....

One--I bought wilton Neon fondant package and added the purple to my homemade fondant.

Two--I started with a little black color to make the fondant grey then added purple and was also successful.

Along the lines of the other suggestions but hasn't been mentioned yet. When I'm looking for deep hues I start with a premade (I like fondx but satin ice works also, they are different colors though the satin ice is more blue) fondant color (especially for pink, red, and purple which tend to fade) and then add my americolor to it. You still have to be careful with fading and exposure but I find the fondant that is already colored to take additional color better than white and still keep a good consistency. I also have a couple links bookmarked to color charts to give me an idea of what colors to mix to get the color I want. I'm not sure if I can post link so my apologies if it doesn't show up but this is on I use often: http://www.sweetsugarbelle.com/blog/2011/02/color-my-world/ According to that site to get plum you mix 3 parts violet to 1 part Christmas red in the americolors. Also remember that on the color wheel red and blue make purple so you could start there and do some experimenting. Good luck!

I had to play around with this recently as I was making some dinosaurs to match someone's invitations. I tried adding black to the purple and I just really didn't like the result. I don't buy the premade colors, just because I don't have many options locally on where to buy these and generally I don't have the patience or time to order them online. I'm bad at planning ahead haha. I ended up using the Wilton Violet Color and got a rich purple color using that. Then added small amount of the Wilton Royal Blue color until it was dark enough. I use a little bit of tylose powder mixed in, if you let it set for a little bit, there shouldn't be too many issues with consistency. As far as fading goes, I haven't had a problem with fading unless they are sitting out for more than a few weeks, but that may have something to do with the environment they are in. I have used a clear confectioner's glaze also, just a thin coat, that seemed to make colors pop a little more as well. I feel like it takes longer to dry to where they're not a little sticky then what they say though, so if you don't have the time to allow for a day or two of drying, probably not a good choice. Here is a link to the glaze (this is just a random shop I found that had it online, not where I get it) I also put a picture up of a dinosaur that was one of the deeper shades of purple, this one is slightly lighter than some of the purples, I thought it got too dark at one point, but you can get a good idea of how that color mixture works.
http://www.fondantsource.com/peglfoco.html

Sorry, I'm new as of an hour ago to cakecentral, guess I couldn't give you that link. Send me your email if you would like it

Replying to an old post, but just in case someone else out there is looking...

 

I used Americolor Red Red and Violet mixed into a hot pink Fondarific pre colored fondant. It was almost an equal amount of red and violet...but just play around. I got a nice bright (yet darker, if that makes sense) eggplant color.

This was helpful! I am looking to get a deep deep purple and really struggled. Thanks all for sharing!

Here is a pic of dark purple flowers I did over the weekend.  Not sure if dark enough for anybody else tho.  I mixed deep blue into my fondant, then added the purple color.  Still was not as deep as I wanted it to be so then I mixed violet luster dust with midnight blue petal dust and was happy with how the color stayed.  Have done this before and they do not fade.  HTH

I used the luster dust and lemon extract mixture today. Marvelous!!! I finally got my paint. It was much easier to make these in white and "paint" them. My life just got easier. Just may stick with this thing. : )