Yes!!!! I tried it and it worked great. You really can make your own custom colors this way.
Also.... save the pastel chips and put them into little containers marked "Reds", "Yellows", "Blues"...and so on... then when you want...just crush and make a new pastel...
No telling what color you will get, and chances are you will not be able to duplicate exactly, but that is half the fun.
Also, the book said to save your pastel dust from off the ledge of your easel. It said that the dust would make wonderful browns and grays.
As much as I seem to be wasting here lately, I think I will try this "save the dust" tip in the near future and let you know.
See you in the Cafe Chat Room
...Or, stop by ... the Virtual Cafe Guerbois