While white shirts sometimes look great on other women, they bring back horrifying memories of Jr. High gym uniforms and tucked blouses ballooning out over circle skirts. I don't know why white shirts are always on the "lists" of items every woman should have. In the first place, I don't look good in white. I hate to iron, and every no-iron shirt I've tried still has to have some ironing.
While I never seem to spill on a black top, whites are stain magnets, although I do manage white jeans pretty well. So I've banished white and most off-white tops all together.
On the other hand: I once saved a photo of India Hicks from Vogue. She was wearing white shirt, black blazer, dark jeans and high high heeled sandals and of course, she looked fantastic. Sigh. I think Una, with her great shoulders and body shape, could look just as good in a white shirt, so I'm inclined to encourage the hunt to find the perfect one.