I had my male beta just shy of three years, and during the last year, his dark red/orange color had significantly faded.
If they are not too old and the female is ready, then they will mate.
the size of it's fins and body
He might be getting old. If he is paler and less active, than he is sick, old, or unhealthy.
A Male Betta will grow to about 2.5inches of body length and a Female will grow to about 2 inches of body length. A Betta is fully grown at about 6 to 8 months a Betta is very old at 30 to 36 months.
A male betta can live 3 to 5 years when cared for properly. This may seem less when you own the fish, but this is due to the fact that male bettas are usually a year old when you buy them in a store because they are not sold from breeders until their fins fully develop
you ask him.
Adult betta fish, specifically the males, will grow in the majority of their fins as juveniles. When you see bettas in the stores for sale, they are typically around 2 years old already since it takes time for their full finnage to appear.
their colors dull. for example, instead of bright purples and blues, they would be a dull lavender or baby blue.
Betta fish grow paler and less active when they are sick or old.
by the smell
A nine month old betta is already full grown, so yes.
A betta normally only lives 2-3 years, so it would be around 70 years old in "betta years".