I bought this Mahonia from a large nursery last week. It was in a greenhouse tunnel and much more yellow leaved than any of the other mahonias that were there. It appears perfectly healthy, and has sat outside since I bought it - the leaves at the top are still very yellow (the leaves at the bottom are a dark green).
There were no labels on the mahonias, and the nursery did have a few unusual plants so, I'm wondering, is this a new strain of mahonia that anybody knows about or does it just need some more time for the yellow leaves to turn green again?
Thanks for the suggestion NanTheWiser. It looks like brand new growth might be purple fading to yellow from an image on Google search whereas I've got yellow darkening to green leaves. I shall keep this in mind when there is new growth.