Unless its a boot, the light green of her right heel bleeds onto her stocking.
I think it's just the style of her boot. The way her feet are lined up doesn't make it too clear, but her right foot is flat on the floor and her left on her heel. The way it's drawn, the sole is actually from her left foot, so the light green isn't bleeding.
To be honest, I thought you were talking about that red dot on her leg from that Kiwi thing. I know it's probably there on purpose, but it does seem sort of out of place.
...
Man, I don't normally pay this much attention to pictures.