I finally got the dominant male displaying to a mirror. I tried very hard but it appears impossible to photograph. I will try to draw what I saw.
EDIT:
I put it on a green background to make translucence visible. The parts of the fins with some faint green in it are translucent. The borders between colours are all very faint but that was really hard to draw. This is just to give an idea of the colours that are in it. In fact, there are no distinct colour bands except the blue ones. The others are more vague without clear separation between each other. The white/blue band in the caudal is also slightly translucent.
This looks like a bintan variant. I have two other bintan-like forms(Sentang and an unknown one) which look different from this one in reality.