Board Thread:Movies/@comment-35016591-20180316174647

Hello everyone!

Thank you for taking time to read my question.

So I was watching the age of ultron and Bruce says to Wanda-"I could choke the life out of you and never change a shade."

Choking the life out means "beating the *** out of someone" if I'm right but what does the phrase "never change a shade" mean here?

Does it have something to do with Bruce turning into hulk? 