Disease Sick Or Normal?

[joshrm115]

Just got two new oscars a I noticed they r starting to turn yellow after two weeks and I noticed this after a 50 percent water change and a Chang in conditioner all tho my tap water only has .25 chlorine level without any conditioner. ammona level is zero so I don't kno is this normal? Could this be there colors and becuz the new tank they where hiding there colors??? Plz help me they r eating and don't seem stressed

 

[The chilly dipper]

this is very normal oscar behaviour,
they can change colour in the blink of an eye.

so long as your water conditions are ok there is no problem