blue-white does seem like a better translation. Or Bluish-white. Blue and white suggests discrete color patches.
EDIT: I think the important thing here is this is a weird concept that has no literal translation in English. My understanding, now, is that this refers to an object which is specifically blue and white (order unimportant), like the Finnish flag. It is actually discrete patches (though apparently gradients are OK). To an American, the concept of Red-White-and-Blue maps OK (except with different colors). I expect this exists in many cultures, but that's all I can offer. :D