I have a tiger oscar. Certain parts of him are a different shade of grey. Sometimes it looks as tho he is changing color?? Like from dark grey to a light grey... Why does this happen? Fear?

This happens for a lot of reasons. Stress, water conditions, mating, diet. Lots of reasons.

I brought home two adult O's that I rescued, long story short I have had them about 6 months now and just realized they are both Red Oscars. LOL, There color is just starting to come back. They were kept in a 35 gallon tank with 3 large plecos. and about 18 feeder gold fish.

Now they are in a 122 gallon tank with no tank mates and lots of filteration.

moreover, they really change color as they matured.
vibrant color is always an indication of healthy fish

Sounds like there a lot happier now. I notice it most when I spook him or change things in his tank, or move him to another tank. So I suppose that makes sence lol.thanks for the fast reply

No problem and good luck with him. The one warning I will give you is that they are addicting. LOL. I started with 1 tank and now I have 7 large tanks running. LOL

lol ya i agree i had just my o's now i have a live planted aquarium with plans once i get the money to move my o's to a 220gal and make the curr home a live planted aquarium too lol i am with nicki on this i might even do another oscar tank but with the o's i have seen the tigers are more pronounced in color changing mine when they get feeders get dark and when they square off get real bright

Mine allways shows his mood by the colour of his face.
It turn pale while usually he's olive coloured in the face.
When he's pissed or scared or grumpy...

you might want to check this post of mine to give you a indication of how o's chaneg colors www.oscarfishlover.com/index.php?option=...atid=57&id=39224