At first I could not figure out why they gave the bandmates different color shirts. It looked strange to me, being the fan I am. None of the colors went per say with any real theme of theirs. Then I realized, the Foo-Bot that the alien is holding has colored circles next to each part. Those circles correspond to the color shirt the band member is wearing.
I always liked that in the JJP GNR, if you knew what it meant, you could glance at the emblem in the middle to see what band members you needed still to get to play a song. I think they did a nice job here. In GNR, you may know that Slash wears a top hat, and Axl has the mic, so you would get it. But in the FF pin, you don't need to know anything about them. Simple color matching.
Let the color blind complain for themselves. It's not your fight.