Kermit the Frog Green

A really ugly and tasteless shade of green.

or

A term that is used to define something (mostly a choice of color or decor) as gross and overwhelming.

Elmo: Oh wow, look at that fancy car! I want one of those in Kermit the Frog Green!

Ezruh: Elmo, you have no taste. Everything looks hideous in Kermit the Frog Green, anyone with a brain in their skull could understand that.

Elmo: Oh be quiet.