Very nice color and barring on those feathers. I've never seen a Spruce Grouse down here, but we do have a couple of Ruffed Grouse that visit our mini crab apple tree when it bears fruit. They've been visitors every year that we've been here, late summer into fall.
"A man may smile and bid you hale yet curse you to the devil, but when a good dog wags his tail he is always on the level"
I don't see anything wrong with it, purple or not. I think the fish are also going to like it as well because from what I have heard and witnessed myself, some trout seem to like the shade of purple, and if I remember correctly, brookies love it.
Good looking fly!!