Move them to a sunnier position

The nandina are in the sun most of the day except for a couple of weeks around the winter

solstice and was taken about noon DST. This was a working concept for the patio plantings. The Nandian are to the picture right of the patio steps behind the bend in the retaining wall. There is a plasic 4" pipe that runs about 12" below the ground that parallels the wall and goes down hill to the picture right.

When we planted them 5 years ago it seemed like a good are from what we had read, but as I have said they have never gone beyond yellow to read.

They need winter sun. Where do you live? Maybe your winters are too mild.

OP; about 20 miles east of Raleigh NC. The picture shows the sun at Noon, in the morning and afternoon the nandian get light even in as the solstice