The fashion trends of the 1970s had started taking root in baseball. Long hair and loud colors were starting to appear on team uniforms, including the Astros'. In 1971 the Astros made some changes to their uniform: they kept the same style they had in previous seasons, but inverted the colors. What was navy was now orange and what was orange was now a lighter shade of blue. The players' last names were added to the back of the jerseys. In 1972, the uniform fabric was also changed to what was at the time revolutionizing the industry – polyester. Belts were replaced by elastic waistbands, and jerseys zipped up instead of having buttons. The uniforms became popular with fans, but would last only until 1975, when the Astros would shock baseball and the fashion world.