AH HA! Thank you so much! Now i just have to figure it out

Actually, i already have the six rainbow stars from cloud city. I have 7 left and need 8. i am obviously missing one from somewhere!

I have found:
The old windmill
The lost cave
Lost Wonderland Mine
Secrets
Escape from the Void (8 lvls in all in the Void)
The Secret Cave (in the Volcano)

I'm not sure what else was actually a rainbow star level...? So confused. I've tried moving every direction on each level but can't find ...

I am probably missing something easy, but I only have 7 rainbow stars and cannot access the final level! is there a secret level somewhere that i missed?