American Apparel's Poppy is an-almost neon orange cream. My camera picked up the color fine, but when I went through Picnik to add the watermark, the color changed and I had to tinker with it. It actually is this bright, though. It's as bright as it can be without actually being neon.
Below, I have it stamped with Red Angel plate 103. For the stamping polish, I used American Apparel's California Trooper. I did a really hasty stamping job because I was losing the light and I wanted to photograph it today. This was my first time using CT as a stamping polish, but I think it will work fine if I am not rolling the stamp on as quickly as I did for these pics.
Below: Yes, it actually is this bright. I also think it's one of the few colors that can actually make me look as if I have any melanin in my skin. Like, at all. The formula is nice. It takes two coats for full coverage.
Below: American Apparel Poppy and Sinful Colors Thimbleberry side-by-side. They aren't dupes, but they are definitely close. I would say you don't need both.