dark purple kupang damsel stress or??

[gmoney243]

My kupang damsel has been in my 10g for about 5 days now and has remained a very dark purple instead of the blue it is suppose to be also he hides a lot when he sees someone but I catch.him out when he doesn't see anyone. Is this normal for new marine fish? Or is he stressed for some reason.
Ammonia nitrites nitrates are all zero ph is 8.2 temp is 79f. using. 150 gph powerhead he a acts same whether its on or off. I did yesterday see him blue b4 I turned lights on and he saw me .. but he went purple soon as I was spotted.
This is my first marine tank but I have a 40g and 150g cichlid tanks so I'm not complete noob just new to marine tanks. Thanks for replies

 

[btldreef]

I'm assuming you are referring to the damsel commonly called an Azure Damsel (Chrysiptera hemicyanea)?
How "blue" they are varies.
He may still be adjusting to the new tank. I've always found young damsels to be shy, but they become bolder and more aggressive as they mature. Is he eating?
Just a side note here: this fish is really not a good idea for a 10G, especially if you plan on keeping other fish in it. Damsels are aggressive, ALL of them can be, even the ones that are "more peaceful."