With shade gardening, there’s a difference between plants that are shade lovers and shade tolerant.
Hostas, for example, are often considered shade lovers. Some do require shade to produce their best leaf colour. Yet, most hostas are simply tolerant of shade.
And here is my baby corkscrew hazel (Corylus avellana ‘Contorta’), which does best in full sun. However, with a bit of morning and afternoon sun in my front bed, it tolerates my shady garden. It gives me fewer spring catkins, but still makes the twisty stems that give this plant the common name, Devil’s Walkingstick.
[Oops, I stand corrected: sharp-eyed reader Nick points out that Devil’s walkingstick is the common name for Aralia spinosa. Corkscrew hazel is commonly named Harry Lauder’s Walking Stick. As far as I can gather, Sir Harold Lauder was a BMOC in the garden-design department, mid-19thC. Please feel free to correct me!]
HOWEVER (and you can see by the typeface that this is a big however), like many plants living in less-than-ideal conditions, corkscrew hazel does have a tendency to sport or revert back to its natural form, putting out straight stems rather than curly ones. The same can happen to plants with variegated foliage. Under stress, which is what less-than-ideal cultural situations create, they can gradually sport back to green.
You can’t tell the plant: cut it out! But you must cut it out yourself, pruning or pulling up the unwanted straight or green growth. Once sporting begins in a plant, it will likely recur. Besides marring the appearance you selected your plant for, the original form is usually more vigorous and can take over.