Glo-lights definitely look orange or coppery in a school. They look drab at the store compared to other tetras, but once I got them one and they were in a planted tank and their colors became fully vibrant, they were lovely. Definitely an underrated fish!
If you get ember tetras, please post pics--like Craigthor says! Would love to see.
Oh, and I have some gold tetras. They're great, but their color is a light pale-lemon gold, especially under bright light. Very pretty but not a rich, dark color. And it's iridescent for sure.