Males - Extended Fins. Facial and body Worms on good examples. Venting (2 opening under the fish, these are the Vents. (...without writing a scientific journal on it)) Males look like this oo
Heres my male green. (i do tout this photo all over the shop, but hes a good example on sexing.)
Notice the Above Points.
Females- Less Facial (and body worms) The fins will be less extended. The Vents will look like this o0 (the larger hole are the rear is the oviposter

)
An awful example of my gold female, but shows the lack of markings etc
Both sets of rules are true to Reds, greens, golds, turcoise, notatus, rotkeil... all sub species of Heros efasciatus (the severums your keeping) both natural and line bred.
Like i say, i would be interested to see a red female. Due to the lack of markings on gold females, i imagine a good example will be very difficult to find. ill have a google.
Best of luck
Craggy