Seeing that it has a considerable amount of yellow on it now, yes, it's safe to assume this fish a male.
Ideally M. lombardoi should exhibit a single well-defined eggspot on the anal fin of the male. He should turn yellow as he matures. Females should retain the blue juvenile coloration and exhibit no egg-spots.
Dominance plays a role in color change. Subdominant males may appear female until there is no one to pick on him or he outranks the dominant fish. Females may take on a yellow hue if being relentlessy pestered by a male. Unfortunately for some reason, perhaps inbreeding or hybridization, a number of tankbred M. lombardoi will show more than one eggspot, on either male or female.