Spotted a odd trout all black head and white body ?

[deaone123]

So was searching for some trout holes managed some smallies n bluegills and stumbled on a shallow patch of cold water on the raritan with 25+ rainbows in one spot in a assortment of sizes largest was pushing over 30 inches & would hit my lure but not commit
- i have costas and the fish were shallow so i could see everything and i spotted 1 odd trout that stuck with the pack but it had a all black head and white body with no pattern just solid color and was def a rainbow by the look and shape , this is going to bother me lol anyone every see a deformity on a trouts color pattern like that before?