This is relevant only for background information, I'm sure, but there were marbles made like this in the latter part of the 19th century. Most were white-based layered with a medium blue, some were white-based with a medium green, and others were white-based with both blue and green, alternating. Rarely, one of those will also have thin lines of pink.

They seem to have been made mostly in Germany, although there are a few rare ones that are a little older, apparently from Holland, that are white or cream with brown.