I recently purchased, a new commercial food Nature Zone Baby Iguana Bites which is green, and I crossed my fingers it would appeal to him, and it did work! He still poops 1-4 a day, hasn't changed his appearance, very kind and calm iguana. I can see he is slightly growing as well, I am looking forward to trying other greens and vitamins. I think he might like the cactus leaves and green beans/snapbeans.
Here is the link to where I bought it from, would be nice to have thoughts on the nutritional value as well.