A Question about Color Singlet State invariance under Unitary Matrix

[james228]

TL;DR Summary

After applying U on the color singlet state I am not getting the same color singlet state back. How can i show this color singlet state is actually invariant under U?

 

[Gaussian97]

You should show us your work, then we may be able to see what's going on.

 

[james228]

I did figure it out. Thank you so much!