Red Dragon holds its red color better than any red dissectum I have seen, but most of the red-leaved Japanese maples will green up if planted in a lot of shade. My Garnet gets similar light conditions to yours, and it's nearly all green by June. However, my Red Dragon gets full sun from about 9 a.m. to 3 p.m. and keeps its deep red color all through the growing season. My Crimson Queen gets sun from about 10 a.m. to 4 p.m. and holds its color nicely as well, but not as much as Red Dragon.

You might consider moving your Red Dragon to a spot with more sun if you want to keep the red color, but I would wait until late fall or winter to do that.

I agree i think just about any red JM will green out if left in shade PERIOD.... red dragons do keep their color in partial shade at least mine does but it seems you have planted this cultivar in the wrong place TOO MUCH SHADE...agree move this fall ...dragons can take alot of sun but not knowing where you are from the old addage of morning sun afternoon shade or dappled shade ( better) is in order....David