Will and grace - Will explaining "wrong" to Jack and Karen

I’m trying to find a Will and Grace episode where Will is trying to explain the concept of “wrong” to Jack and Karen.
He tried many different ways of describing it, but J&K are clueless,
until he said “It’s like brown purse with blue shoes” which causes them to recoil.
It might have been a blue purse and brown shoes.
My Google-fu has failed me. Any suggestions?

"Like wearing a brown belt with black shoes".
S04E06 Rules Of Engagement

I’ve never understood these arcane notions of sumptuary ritual.

Whew! Thanks do much