The blues are quite variable in the synspilus/melanurus group. I have a large male (~13") that is about 5 years old and presently, is predominantly light blue with yellow to the rear, and a light pinkish head region, much like the last pic you displayed, @manu8__too. About 2 years ago, he looked like my first pic (it is him). This is the red form of Paraneetroplus melanurus. I do have another one, same age, size and sex and he is at this time much more colorful, like my first pic. On the other hand, the orange form from Lake Peten in Guatamala, is distinctly different, showing a much deeper blue (almost black at times) over most of the body, with a lot of orange . This is him in the second pic and the pair in the following one The fourth shows the 'orange' form when about a year old ... lots of orange which tends to come out more when courting and spawning. They are in my pond right now and are doing great out there.
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