Let's take some small steps through the spectrum.
Small steps - color cycling
For this quest, I want you to go to the Machine and build a sprite that cycles through the color spectrum.
Your sprite will need to loop through the various colors, returning to it's original setting eventually (and potentially keep going, depending on how you build it).
Colorful cycling; all right! Now choose another quest and keep working on your spells.
If you'd like some extra loot, drop by your Codex and write up a few notes on what you learned today, either in this class or another one. (Of course, Loremaster Rellim is more interested in what you learned about yourself and your learning than about any particular subject...)