In the movie Green Lantern (2011), Sinestro has a yellow ring because they were out of green ones. This is a reference to how I probably should have paid attention to the
Sinestro Corps Inspired Silver Ring Yellow Gold Plt Jewelry
Justice League Unlimited - Mattel - Yellow Lantern Sinestro (loose)
DC UNIVERSE CLASSICS 6" SINESTRO YELLOW LANTERN CORPS NEKRON BAF WAVE 20 LOOSE | eBay