I went back and checked all my old Khaki duckling pictures. I found no connection between bean color and gender. I had female ducklings with both light beans and dark. I only had two drakes one had a light bean, the other kind of half and half. I did find the ducklings with the prettiest head shape from the side were my drakes but that isn’t definitive either. In a few weeks it will be obvious. Either by voice sexing or possibly the feathers above the tail. Solid dark feathers are drakes. Light, two-toned feathers are girls. Dark, two-toned feathers can be either. In the picture, the Khaki on the left is female, right is male.