fish colour fading

Question
Hi Chris
I am not going to be of much help to you with info.  I have inherited a tank (90 gallon I think.  The only fish I know are barbs, clown loaches, a large cat fish with really long fins, some bright yellow fish and what were iridescent blue fish.  Warned you I am hopeless.  I am looking for advise as to why the iridescent blue fish have faded to a pale light blue.  I change the water, about 30% once or twice a month.  Can you help an extreme novice please.  Any advice would be much appreciated.
many thanks.....Kate

Answer
Hi Kate;

Without knowing what kind of fish they are I really can't say what could be going on. Fish will change color according to mood, diet, breeding condition, water conditions, water temperature, etc. If you could get some photos of them maybe I could take a look and give you more info. You can attach one to your question or upload to a free image hosting site such as flickr.com, photobucket.com or any other and send me the links to your photos.

At Your Service;
Chris Robbins