Female dwarf gourami do not have much colour. Most are very dull, pale brown. Some of the powder blues have a bit of blue on them, but not nearly so much as males do.
The posted pic is male, no question. Many fish stores don't even sell females, because they are not as pretty and thus do not sell nearly as well as the boys do.
Sudden death in these fish, or a quick dwindling away, is, sadly, very, very commonplace. I no longer try to keep them, I got discouraged at the many deaths.
They are basically quite shy, need heavy plant cover both planted and floating, and to break up sight lines if there is more than one of them. No bright light, if there is not a lot of floating plant cover to shade them. They dislike much current in their water, and are generally just not easy to keep alive for very long. It is really too bad, they are so lovely, and I truly find them beautiful.