Need Advice Please!!!

[JC Germ]

Hi all
Need some advice I have a black ribbon eel for about a year now he is doing great, eating like a beast
(Small blocks of hake and shrimp and live food once a week or 2) any way the reason I need advice is
He is changing colour he is turning Blue is this possible that they can change to blue ribbon eel???? Or is something wrong because he looks extremely healthy!cnfzd:

 

[BigAl07]

Here you go...

The Black Ribbon Eel is a juvenile. The Blue Ribbon Eel is bright blue with a yellow mouth and is the adult color of a mature male black ribbon eel. A female Ribbon Eel is yellow.