Ah! You don't want to blend with multiple preset colors in between, but using a different color model I suppose! The above looks like the blending was done in
HSV or
HSL space. (Don't know if right- or left-handed hue, but that should be simple enough to try out.) So instead of blending using
RGB, just do it in
HSV/
HSL. That should get you pretty close to the above result.
"When one person suffers from a delusion, it is called insanity. When a million people suffer from a delusion, it is called religion." (Richard Dawkins)