Did Muhammad Ali always wear white and black shorts in fights?

No, there have been several instances when he didn't. For example, his first fight against Liston he wore white shorts but instead of black they had a red line down the side and waistband. He also wore these against Ernie Terrell. Against Henry Cooper Ali wore red and white satin shorts and in "The Fight of the Century" against Joe Frazier he wore a beautiful pair of red and white shorts again but this time they were velvet instead of satin. He also had a matching robe. They were the most stunning looking trunks I have ever seen. He also had red tassels on his white shoes that completed the look.