Sexing Honey Gourami And Possible Problem

Generally, male fish are more colourful, but they may still be juveniles so can't be sure yet if 1 male and 2 females. Again, @Sue is much more experienced with gourami and may be able to advise.

Is the fish with the dark patch displaying any other symptoms, visually or behaviourally?

Male honey gouramis of both natural and yellow colour develop a black throat, though it's less obvious in yellows than in natural coloured males. It is more intense when mature and in breeding mood. Your fish in photo 2 is a male settling in and maturing.
It's harder to tell in the first photo as two of them are partially hidden by the plants.


I've had yellow honeys in the past and this are the indicators I've noticed, once they've settled in.
Males develop a black throat, even if it's just a hint.
Males tend to have orange colour towards the tail.
Males tend to swim around the tank in an "up front" sort of way (especially in shop tanks where there are other males)
Females often have a broken darker line running from nose to tail though not all females have this.
Females have maybe a hint of orange at the tail or no orange at all.
Females seem to spend most of their time searching the substrate for bits of food.


The attached photos are a pair I once had. You can see the black throat and orange on the body near the tail of the male and the broken dark line and orange only on the fins of the female.