A spell for prismatic mages

[Crake]

So I've been playing a prismatic mage recently (initiate of the sevenfold veil and whatnot) and my DM has opened up the floor for custom spell design, so I put this together. I'm probably being a bit optimistic setting it at 8th level, but otherwise, how could you guys see improving/balancing it?

[Kazy]

I like the idea. I do think it's a lvl9 spell, specially because of the magic immunity.

Either way I'd definetely add an expensive spell component. Summoning a prismatic golem that can tap into and is created and given form by the intrinsic magic of colors seems something that would require a strong channeling tool.

As a big outside-of-the-box thinker that I am, a suggestion would be some kind of labrated prism or a colletion of small precious stones, one of each color.