I've grown bell peppers for years and haven't seen a problem like this
It is a Blushing Beauty, planted in a container as a seedling purchased
from a local nursery (and not Home Depot or other big box store... I
can't make that clear enough!). In its infancy it looked just like any
other pepper, but as time has gone on it has changed appearance.
It has not developed the lush, broad deep green leaves that peppers
have. The leaves are narrow. They are uniformly more yellow than green,
and they are also uniformly creased deeply along the central vein
although not outright folded. I can't detect any new growth on the plant.
I have never grown this variety before, but I can't imagine that it
would be significantly different from other peppers.
They nursery people have no idea what could be happening to the pepper.
They even had me bring the container to them, so that they could have a
look at it (wisely, they made me keep the container in the car and they
came out and look at the plant rather than have me carry it and whatever
its problem is into the nursery environment).
I have dealt with TMV and the other ordinary afflictions of peppers
before, and this is not any of those. I've looked it over for
infestation, and have found nothing. I may just be overstressed from one
source or another, and I may have to give up on the plant and hope for
better luck next year, but before I heft it into the bin I figured I'd
ask you guys first. Wish I could provide a picture, but my camera has
shrugged off this coil.