You can do this by going into the preferences window and under the programming tab selecting seperate by color. You can then record three seperate IPCB scenes with each color flag at full (Cyan, Magenta, Yellow) for the fixtures you want to effect on stage. This should allow you to mix colour using playback faders. Then if you want to record this color mix into a cue you can "suck" the colour parameters for those fixtures into the programmer/cue editor.
I hope this works for you in a way you were hoping for.
When separate parameters is turned off for a parameter group, touching one parameter in that group will touch all parameters in that group. This is usually desired for the colour group because you will usually build your colour palettes using slotted colours and CMY and CTC. Having a colour palette with only Cyan in it, for example, wouldn't take full advantage of the palette system.
If you'd like to leave separate parameters turned off for colour and would still like to build handles for CMY, you can set the level for cyan, knock other colour parameters out of the programmer, and then record just cyan to a master which you can make into an IPCB fader. Wash, rinse, and repeat for magenta and yellow.
