@Kaktus how did things turn out with your white Adeniums? I have been awol from the Garden.org site for some time, and just saw your post.
Of the five variegated seedlings I had, the two weakest didn't survive, but the other three all grew into beautiful plants.
I did have a few "albino" seedlings that did not develop chlorophyll. These didn't last long as, not having chlorophyll, they could not feed themselves; they died as soon as they used up the food stored in the seed.
