I've never tried it, but I can make some predictions.
--feathered feet, but not as many feathers as the Brahmas have
--pea combs, but larger than the pure Brahmas have
--some pattern of black on each of the offspring, but probably not quite like the patterning on any of the parent breeds
--white barring on all of the chicks (inherited from the Bielefelder father, of course)
--sons from the Dark Brahma mother should grow up to have black breasts with white barring like Bielefelders do (or like Dark Brahmas + white barring). Sons of the Light Brahma will probably have light breasts.
--sex-linked coloration: daughters have gold (or red or brown) in their feathers, sons have silver (white) in their feathers. The sons may get some amount of red in their shoulders and yellow in other areas as they grow up, rather than having the clean white of their mothers, but should be pretty clearly different from their sisters. I'm not sure if the color difference will show up in the chick down, or if you'll have to wait for them to grow some feathers before you can see it.
--they will probably grow up to be big birds
--females should lay brown eggs
