Acanthurus tristis
 

Anyone know if they change colors as they age or do they maintain the same colors?

Nvm found it on google, they go greyish

the yellow on the fin goes black. they do keep the stripes
http://www.dejongmarinelife.nl/sys_f...zoom_thumb.jpg
adult
http://www.aquariumreference.org/Pho...is_12782j0.jpg
sub-adult

http://www.liveaquaria.com/images/ca...89370-tang.jpg
juv

just for reference