What Disease Has My Sunset Gourami?

[serbanmm]

Hi all! I have a problem with my sunset gourami. I bought him1 month – 1.5 months ago and then he has not shown any sign of illness. After three or four days it appear on his skin and fins brownish-blackish patches. Since then (with 1 month ago) he doesn’t shown any changes even he’s slightly worse. However, he’s eating and swimming normally but he is a little more agitated than the other fish. I attached a picture with my fish and I hope someone to know what he has! Sorry for my English but as you noticed I’m not a native English speaker! Thanks!

PS: My aquarium: -60 litters
-heater, white light bulb, water filter
-fishes: 1 pearl gourami, 2 sunset gourami and a betta male
-5 plants
-water temperature around 82 Fahrenheit(28 Celsius)
-water parameters: 0 ammonia, 0 nitrites, 0 nitrates, PH:7.8

 

[serbanmm]

I have more pictures...i hope to be more accurate! The fish looks brighter because of flash-light! Because i can't upload more than 1 picture here is the link to other pictures!

Fish Pictures

 

[Gill]

Hi, There is nothing Wrong with him. That is just his natural colors coming through. He is a Red Robin Honey Gourami and Is a Male so the Fins are changing color to his mature colors.
Some say that Red Robins are a color morph or are color fed to be red. In General IME the red fades over time and the more orange color starts to come thru.

 

[serbanmm]

My sunset gourami it's darken than ever...so, now he have the caudal fin almost black...and his other fins are also black....and of course that on the skin the patches are darker...so...someone have an ideea what it is??? In the same time he's eating and swimming like a shark...soooo...i'm so confused!

 

[serbanmm]

Here are some new pics( are not so great but you can see the problem)!

PICS LINK