I have had my betta for about 2 weeks. I have noticed that he
is changing color on his fins from red to blue. Is this
bettas sometimes change colors? The answer is YES. Most bettas will
change color as they age, some strains more so than others, some
very fast and some very gradually. I really wish you had described
your betta's original color so that I would be able to better help
you. I assume it is a pet store betta, in which case it is a
"mutt" genetically speaking, the result of random
breeding. Most of these bettas have a lot of washes and many are
multicolors. Let us explore what can cause a betta to change color
and let us also take a glance at different strains and how they can
be expected to change color wise as the bettas mature.
Let's start with why would a betta change color?
|Multicolors: These have
random colors on their bodies and change colors as they mature,
usually the balance between the different colors may evolve. I
suspect you have such a betta (consistent with the fact that you
have a pet store betta and most pet store bettas are multis).
bettas will not only change in the same way as the solid bettas
above, but also the tip of their fins will change. Some start
with solid fins and then the tips turn white or clear (or black
if it is a black BF pattern). The colored ban will also change
as it may grow or shrink, be even or become uneven. Hence BFs
may not stay the same as when you bought them.
||Marbles: Marbles are the
most changing of all bettas. They change pattern throughout
their lives, some turning darker, or lighter or going one way,
then the next. A black marble may start solid black, then become
piebald, then turn into a BF, then become blotched and then get
less and less black until it is almost cellophane. This is an extreme
example, but not an impossible scenario. It is impossible to
predict what a marble betta will look like in a month. Some
change more or faster than others.
||Diseases: some diseases
will cause bettas to change colors. Usually they will turn pale,
or have red sores, or even dark or red edges on their fins and
tail (fin rot). Worry not, no disease I know causes a betta's
fin to turn blue, so I am sure in your case this is just a
pigmentation change. :))
||Methylene blue: Careful
with it! If you put too much it may cause the fins of yellow
bettas to turn blue LOL. (serious).
Now a quick glance at how a strain color is expected to change overtime: