Without some green in the leaves or some green leaves, the plant can't survive. A plant with very little green will survive but never bloom. I have a variegated violet that blooms profusely but I have worked hard to minimize the white and encourage the green. Also, my plant has never produced a viable baby violet from a leaf cutting - they are always white and when the 'mother' leaf dies, so does the child.
I'll post a photo in a minute.
With these two photos, you can see the progression of my plant. Warm temperatures encourage green leaves and cool temperatures encourage white. The first photo show this winter's growth. The second shows last winter's growth. You will note green leaves in between - those are the warmer months when the plant could utilize the nitrogen in the fertilizer.
So to encourage green leaves, keep the plant warmer but to encourage white leaves, keep the plant cooler.
Hope this helps.