Hi there. I am still really new to growing clematis & am wondering if someone can help me out!

I purchased two diamantina from our local nursery and planted them about a month ago. They were very small when I planted them.The darker foliage is the old leaves that were on them when I planted the clematis, the newer foliage is the bright green. It appears to be all the same plant, and there are lots of these lighter green leaves on the same stems as the dark ones, so I don't think it's something else growing there.

They are mulched and growing next to an arbor. Both clematis on either side have the same light green foliage on them.

Does anyone know why the leaves are a different color? Am I maybe over watering/underwatering? Or is this normal for new clematis leaves?

Thank you for any advice!

Michaela