Albino iguanas have yellowish or pale scales, giving them a unique, distinct look that sets them apart from the regular green iguana. The eyes are another way to determine whether an iguana has albinism. If an iguana is an albino, their eyes will be a red or orange color.
The reason why they have this pale color and different colored eyes is because there’s a defect in one or several genes that distribute or produce melanin. Melanin is responsible for the pigmentation of the skin and eyes.
As a result of this defect, no melanin or pigment is produced which manifests itself in the lack of color in the scales and eyes.
The gene responsible for this condition is recessive. This means that both parents must carry this gene for it to show in their offspring.
To learn more about it I highly recommend you read the Wikipedia page on albinism. It’s quite a complicated mutation to completely understand.