We see and hear so much today that pros are using hybrid strings often mixing a poly with natural gut. However, when I look for strings that many pros use, the color of the gut is "natural." How is it that pros who claim to use hybrid strings and those who use natural gut strings have them in white? For example, Kim Clisjters allegedly uses Babolat natural gut, but her strings are white and not "natural" as the description of the strings state. Another example is Federer's combination. According to TW, he uses a hybrud made up of hybrid of Wilson Natural Gut in the mains and Luxilon ALU Power Rough. Again, the Wilson Natural Gut strings are supposed to be "natural," but they look white.