How unfortunate that they choose to look down their noses at pronunciations which are closer to the original words than the way they pronounce them. Both come from Spanish, and are pronounced in Spanish as koe-loe-rah-tho and nay-bah-tha I've never looked into it, but in Spanish they might be called "Coloradenses" and "Nevadeņos". If anyone knows for sure, please jump in! :0)