You may need a illustrator to comment on this and not a writer, I don't have much to say but praise. She does look very sad, the hair and fur has very rich detail, and I definitely don't think you went overboard on the colors. The red of the apples, her eyes, her belt-thing and the little bag all go together well, I like what the single candle does to the scene and otherwise the colors feels appropriately muted to match her mood
A few small worries, 1) Should her ears look like odd tufts of hair? Something about the way they seem to grow out of her hair and not her head feels odd. 2) Is that tail coming out of her back, or out of her side / arm? The length is off perhaps. 3) There is something odd going on with the anatomy of her feet. I wouldn't have seen it without staring at the picture for so long, but now that I did I can't un-see it. The lines are too straight? The foot tapers too much? I don't know
I'm glad to help. I've heard that thing about hands and feet (although I thought her hands were quite good) from other people too, I wonder why. Just small and fiddly compared to the rest of the body?