In 2012 I photographed three Great Crested Grebe young'uns on Gunwade Lake Ferry Meadows CP, Peterborough. One of the grebelets was much paler than the others and seemed to have some kind of schizochroism or leucism or whatever. It also seemed to be being a little neglected by its parents. As it happened, it survived, and I even saw it last year as a young adult.
I was delighted, this year, to once again see this pale backed grebe, this time in courtship with a mate. It appears that the pale bird is a female (smaller than the other). Here are some shots in the rain on Overton Lake, Ferry Meadows (which joins onto Gunwade).