As you may guess some inventive breeding practise has led to the development of these "balloon" rams
(given the new orientation of the fish internal organs (& subsequent health issues) I'd dead against these sorts of fish
- take care in feeding & husbandry)
"Holland" breed line produced the "red" ram - even the males show good belly coloration & more red overall (note that some wild populations also show extended red)
"Gold" rams typically show pale belly markings except when females are in good condition
"Blue" rams - wild type coloration observed in most wild catch, the blue spangling in that black spot is best indication of female/male
"Electric Blue/Neon Blue" - these sell under a variety of names & color/quality is quite variable (once "Gold" mixes in, color pales & variation in color diminishes), again these are difficult to sex
Shape becomes a good determinant of sex when that blue/black coloration is lost
BUT with the advent of the balloon rams (& now subsequent creep into even "regular" lines), shape is variable
(there's an excellent page (with photo) that summarizes sexing the color morphs but can't find it quickly
- it has been linked here in previous Ram Sexing Discussions)
So just keep watching your trio & see what happens
Note the extended dorsal is more common in males, but females may also show outstanding finnage ... & of course the long fin mutation has also crept into general population ... it's very difficult to find "pure" line rams these days