Lapwing are mildly dimorphic, where both male and female having different colored plumage. However standing alone by itself, it is not easy to ascertain for sure whether the coat of color is black or varying degree of darkness. To see the differences in shades, it's best sighted when the couple are together and luckily that is also a frequent occurrences.

Anyway, the birds usually appear in flock. So the appearances of the various birds within the flock offer a good chance to make the differentiation, now that you are trying to seek out that fact.

With Will would Wander