Why do a lot of your newborn fry have one black and one white eye these molly fry are also very healthy.?

molly fry generally have different coloured eyes when they have a genetic unbalance. Depending on the coloured / specie of molly that you have bred with, as breeding randomly means they become inbred and are not of show / top quality, therefore they are susceptible to health problems and in this case different coloured eyes or abnormal body parts. Fish can be healthy even if they have different coloured eyes, although it is frowned upon if you wish to compete, or show your fish.