Britney Spears returns to brunette for latest Vegas show + really starts to move...

Last night, Britney Spears performed at her 'Piece Of Me' show in Las Vegas. During her second show this week, she debuted brunette hair! Something tells me it might be a wig but whatever. She looks great! A change of hair colour also seems to have done major wonders for her confidence because she was performing with much more vigor.

Either that, or she swallowed some energy pills. Check out more pics and three short videos inside.

Thoughts?