Reading this thread, I have fond memories of working with IT consultants on an ERP project at work! The language barrier between the 'guru' and the 'lay person'.
I can definitely see what Gilrock is getting at regarding dropping a purple 'on' effect on a green led. If the green RGB value is '0' then should the led be on, off or somewhere in between?
Personally when sequencing my AC channels I try to use the correct color where possible, and use what ever I set up for multicolor strings.
Sorry for poking my nose in!!
Yes, I am a 'lay person' but, my point is, no matter which color you drop on an AC element, it is always going to be the color of the element - can't be any other way. Not sure who is not understanding whom here......... 
I am a 'lay person' too, I feel the pain from both sides of this issue!!
It does matter what color you drop on an AC element because of the way that the program interprets the color.
XLights was desir RGB so when you drop a color, it is made up of the RGB values.Therefore, using Gilrocks example, if you drop a purple on a green element you will not get any lights as the green value in purple is '0'.
When you set up the AC channel in XLights it asks you to give it a color, that determines what the program thinks the color of the element should be.
It was not my intention to upset you, rather I wanted to try and help!