I’ve driven a lot of different cars around the world and nearly all check engine lights are orange. Almost all the Google image search results are orange. To be sure I checked the most popular ICE car models worldwide: Toyota Corolla, Toyota Rav4, Ford F-series, Honda CR-V, Chevrolet Silverado. All of those use orange. In fact, the only red CEL that I’ve ever seen is on Minis and BMWs - not the actual physical indicator (which is orange!) but the mini-LED screen warnings.