I found this painting "Self-Portrait (1902)" by Welsh painter and one-time student of Whistler's Gwendolen John on Wikipedia. I have been to the Tate a few times but don't remember this painting. The technique isn't exquisite or anything, but I love the introspective feeling of the painting. I like the green and red color combination in particular. Both the models I'm using right now are red-headed, so I might try a similar color combination on one of my paintings.