Did Shania Twain go under the knife? The singer sparked plastic surgery rumors and showed off pink tresses when sharing a photo on Tuesday, May 7, with countless Instagram users claiming she looks completely different. “I love this outtake from the @hauteliving cover shoot because you can FEEL how much fun I was having 💅,” the star, 58, captioned the shot. “Expect me to be coloring my hair, doing what I dare in Vegas, sorry not sorry!!” In addition to her colorful locks, she rocked a full face of makeup and flashed a smile, but social media users thought her fresh look made her unrecognizable….