I like to keep Photoshop open while I'm editing an effect, cuz trying to make the right color by adjusting RGBW individually is gonna be a bitch.
That way, you can easily make the color you want in Photoshop, look at the individual RGB values in order to produce that color, then use those numbers to get your points right in the effect editor.
And if you don't have Photoshop, I'm sure there are other art programs that are cheaper--or free!--that'll help you do the same thing.
The advanced effect editor is a breeze to use, really. I actually found the simpler editor to be far more arcane.
What?
Photoshop...