I'm currently looking at PX5140 and PZ5140 crystal and the main difference being, the former has a yellow ring while the latter has a white ring. I could not decide which one is suitable for my watch. My Constellation has case 14381 which is two-tone stainless steel case with gold bezel. The dial is has silver finish with gold hour markers and hands. It currently has an aftermarket glass on it and I wanted it replaced with the correct Omega crystal. Which one to choose?
You can get some ideas on what your watch should look like from this thread: http://omegaforums.net/threads/pie-pan-as-code-for-more-expensive.730/ You'll note that the silver rings are generally only used for full stainless steel watches with steel indicies and the very rare white gold versions. Hope this helps, gatorcpa