Try to find the greenest pellet you can. I've seen some that are almost yellow. Mine is fairly green. I've seen greener, but this brand (Albers), works for me and for my bunnies, and switching it is stressful on the rabbits so I avoid it if I can.
The greeniness (yep, I just made that up), of the pellet really says how much hay it has in it. You want to find a pellet that has the first ingredient either be Timothy or Alfalfa Hay. It's totally fine to have an Alfalfa hay-based pellet, as long as you don't feed your rabbit Alfalfa Hay.