Yes, the coloration difference could be due to wear-and-tear on the scales.

There was another specimen in the same locality which has the tornal part of one hindwing missing. I was lucky that the pristine specimen was willing to pose for me for a fairly lengthy session, although it occasionally took off to chase off intruding forget-me-nots. It was a pity that I did not have my tripod with me for better shots under the not-so-ideal lighting condition.

Horace