Here is the colour combination as suggested by
based on this colour sheet: [link]
, which came out a male dragon.
White markings like the D-gene overlay black ones like the S-, F- or E-gene, since they block all the pigments from certain areas.
A good indicator for whether a dragon is male or female are the horns. In adult males, the horns are usually longer than the ears, in females shorter. Also, males have longer neck feathers, wider necks and often a little goatee, and they are generally larger and fluffier.