Dark leaves on clematis

[lostinthejungle]

Hello there, wondering what is causing the leaves on my Clematis President to go so dark. Apart from the colour there is no sign of any infestations, diseases, or dry/dead patches, just very sparse foliage (despite a great show of flowers this second year after planting) and the colour of many of the leaves. Some kind of nutritional deficiency?
Suggestions appreciated, thanks! :-)

Autumn :)

Ah, should have said. Been like that from the very beginning when I planted it year before last.

Do new leaves come out green and then go that colour?