I can honestly say I've never seen a BMW that looked good with color changing paint, and all of the pearl I have seen besides some of the factory colors looked bad too.
In my opinion, the E30 is too boxy too look good with that type of a color scheme. Those colors look best on curvy cars that really accent the change. On E30's, it will look like the hood is red and the fenders are purple, and the doors are blue. It just isn't right.
If you had something else, I'd say go for it, I think the paint is cool, but on an e30?
But that's my honest opinion, and I don't mean to flame.
Not to mention the cost of it, you could buy your whole bodykit for the extra price of adding the color change.