confused, Need lots of help

I am confused. My dear Lizzy means the world to me. I need to know if she's a rhino-iguana or a green iguana, she's got the horn on the nose, dark gray on head and upper spine, but the rest changes from dark green or gray to a light yellow to a reddish color. I've cut down her potassium intake, but many of the colors seem to very, often in changes of background. I want to be sure she is getting the proper diet, etc. Right now we're playing it by ear so to speak. We took her in because someone was giving her up and asked if we'ld take her. I felt bad for her because she had obvious signs of abuse, neglect, and she was in really bad shape. I knew enough to get her back to health, (lots of veggies). She's perky and happy, but I want to be sure, I don't know if the breed matters on diet, but if it does, I would like to know. Thank you much. FrancesDowdy

A picture of her would certainly be helpful. Please post one if you can.

it may even be a spiney tail iggy. all there diets are pretty close, so if you dont find out for awhile you should be alright with feeding if greens an veggies.

Most llikely a Green iguana with Rostral horns...

True Rhino Iguanas, Cyclura cornuta, are usually not given up or surrendered. They still demand a fairly decent price in the pet trade. There is one sure way to tell the difference. Only a Green Iguana has the large subtympanic scale on it's cheek below the ear. A Rhino iguana is mostly grey overall, and has 3 large fat horns in a triangle pattern on the nose. They also have some interesting horned scale patterns on the head around the eye and jaw area. Here is a photo of a 4 year old male Rhino Iguana.

Green iguana subtympanic scale

Here's a good photo of a Green and the ST scale on the cheek. Also notice the rostral horns...usually 2 or 3 in a row.