Bob the only thing I know about albo or var is that the lack of good light can turn many plants all green

Keep an eye on it, Bob, but I have the feeling it may just be showing some kind of stress (too cold?). You're right in your assumption that variegation/margination would be present from the beginning of the leaf's development and not something that would develop on an already mature leaf, but HDD also has a point about growing conditions sometimes masking weak variegation. Take 'Elaine', for example. I don't know about anyone else, but the pink margins on that one kind of fade in and out for me. I just don't know what she likes!

If it was true margination on your plant though, I'd expect to see a more definite line between the green portion and the margin. If that margin portion turns papery thin then you'll know it's some kind of stress damage or micronutrient deficiency, or something along those lines.

Guess we'll have to wait and see what develops next.It's definently not cold,and the flourescent lighting is perfect for cryptanthus,and all nearby crypts are doing fine,including 'Elaine'.All receive the same water,feeding,lighting,and temperature. I'm surprised too,that the plant is growing so fast,and so much larger then the mother plant. Something odd going on.
Bob

The crypt.shelf--the plant in question is on the lower shelf tray,right corner,front.(behind wooden planter)
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As a rule for Albo's, more light; less fertilizer.

Here is a link that might be useful: JacksBromeliads