Almost every super or ALS created from the BlkEL or BluEL has the ability to be "pure" white, but can also have pattern.
I have seen Super Fire BlkELs that have a lot of pattern and I've seen some that were pure white, not sure what dictates the bleed through of the pattern in some but not others. The BlkEL and BlueEL complexes are fascinating because of the many different "forms." Some of them seem to be one-offs of others while some are obviously different alleles.