black moor turning gold

Question
I have 1 black moor fish in a 10-15 litre tank. we regularly change the tank probably once every 2 weeks. we've had the fish for over 5 years now and over the past year the colour is changing from black to a gold/red colour. week by week more scales change colour. Do black moors do this or has it got something wrong with it?

Answer
Hi Jackie;

Many goldfish change colors over most of their lives, often going through several color variations slowly as time goes by. Black moors rarely stay black and usually change either to a reddish, chocolate or silver color eventually as they mature.

At Your Service;
Chris Robbins