Mid Winter is the hardest time of the year to find any sort of floral colour. Especially so in colder climates. Even in those borderline climates extreme frosts, driving rain and gales often eliminate or severely damage anything that attempts to bloom. And in the more extreme climate zones outdoor colour really doesn't stand much of a chance.
While even indoors short days and very low intensity natural sunlight coupled with artificial 'dry' heating followed by cold night time temperatures combine to eliminate all but the hardiest blooms in a very short time. There are just not many things that thrive under such conditions.
READ MORE ... e-Book African Violets