AusBonsai

Maybe not a big concern but as this is my first year with maples I was wondering if it is normal for the color change that I am getting on this young Trident. It is part of a multi trunk panting that appears to be healthy, just not sure why some of them are turning pink.
I have been liquid fertilizing every 2-3 weeks.

Probably a lack of nitrogen. When N is scarce the plant will remove it from the older leaves to feed the apex and this will leaves the older leaves coloured. Give them a slow release feed and don't keep them soaking wet all the time. Let them dry to just before wilting point. This will get air into the roots and they should start greening up and extending again as they should be doing now. The red leaves will not green up again. It's the tip of the shoot which tells you if the tree is happy.

Thanks Mike, I will see to it, the mix is free draining and we have a lot of wind so I water daily. Most days the surface is dry but it may be retaining moisture lower down.