In the spring flowering Crocus, Dutch hybrids of Crocus vernus, such as Jeanne d'Arc, Peter Pan, etc., are usually recognized as having the largest white flowers.
Crocus vernus Dutch hybrids are also available in other colors, yellow , purple, violet and striped.

I noticed some new (?) white Dutch hybrids (I was only familiar with Joan of Arc), I wondered if they were larger.

I've also seen Snowstorm and Peter Pan...