I would still call them Barnevelders.
. I don't think the breed standard forces the dark egg issue, unlike Marans. BUT, I would be totally honest about the egg color. I have a few hens from one line that are laying pale tan eggs. But they started out ok, but have faded like most dark egglayers overtime. They are on my cull list. I will keep a few of their pullets to see if the next generation is darker. They will be banded, so I can keep track of them. I'm keeping their offspring because the hens do have traits I like. Both hens are good sized, well marked, were the first to lay, and lay beautiful large eggs. Now I just have to get them darker. LOL