If I was going to be picky, the shadow under the nose seems too dark. Sometimes shadow colors can be made by adding a little bit of dark blue to the color you're darkening. That brown you're using is also on the lips and the hair knot, but it seems like an extra color that's not part of that painting's palette, because it doesn't show up enough to feel like part of that world.
You might want to experiment using just white, black, and primary red, yellow and blue, and mixing your colors. It's a good way to see how colors are part of a collection and feel more natural together.
You don't have to stick with any limits but it's a good exercise. Don't do it on a real painting but practice painting a still life with an apple and a banana or something like that and mix your colors.