The leaves do lose there purple colour and become more green tinged as the year progresses.

I would suggest that the one which has the shrivelled leaves is a) In a windy spot, b) In full sun, c) Not received enough water. Of course it could be a combination of two or even all three that is causing the problem.

Moongrower is correct although I also find that one of my Acer Palmatum leaves on the underside of my very bushy plant stay quite green. I put this down to not getting quite enough sun through the layers of leaves.