Hibiscus flowers that change color in the winter.

I have an hibiscus which in the summer had white flowers with a red centre and red staminal column. It is still flowering now in January but the flowers are totally red.

Other similar hibiscus in my neighbourhood have also now got red flowers. Is this normal and I would like to know the proper (Latin ) or local name of this plant. I am posting a photo of the two flowers in 'name that plant'