This is a cross between a pink hybrid and a red-yellow species, so I sincerely doubt that this white flower is their offspring. It's probably seeds from another nearby cross.
Pollen parent: MM 13-77c (villosa x tulbaghensis) X (villosa x tulbaghensis)
MM 18-186a
MM 18-186b. This is a fascinating flower, with its two-tone tepals, veins, and contrasting inner and outer tepals. If I could get these color patterns with more vivid colors, I think it'd be a lot of fun.