Convict Tangs - all white vs yellow backed

[ZoWhat]

When buying thru a place like LiveAquaria... how can you try to get a yellow-backed Convict vs one thats all white?

Is there a scientific name difference?

 

[Reefer40b]

"Adult Convict Tangs have a dusky white body with six vertical narrow black bars, five on the body and one on the head running through the eye. The upper dorsal portion of the body is grayish green to yellow, shading to white on the belly. The fins are white and the eye is yellow. Juveniles are all white with the black stripes being thin and widely spaced, and with no yellow."
Source:https://animal-world.com/encyclo/marine/tangs/convict.php

 

[ZoWhat]

Interesting... the older I get, the more yellow-bellied I become.

 

[X-37B]

Mine is getting yellow green on top now.
Hard to see under my T5's.
I will take a pic tonight under MH.
Its much more pronounced under them.
Here is T5 and you can see a little yellow.