I think this is a permutation problem.
If you order the Yellow and Orange caps in the following order:
Y, Y, Y, Y, O, O, O, O, O, O, O
It is different from:
Y, O, Y, O, Y, O, Y, O, O, O, O
So to me this is a permutation problem.
Apply formula.
11P11 = 39 916 800 ways
I'm not confident in my answer.