I looked up the details in Orchidwiz... It is Cym Sleeping Dawn (yellow, but with very complex ancestry that could contribute who-knows-what) by Cym Olymilum (white with pink lip and at least one cultivar has pink on the midrib of the petals) So I can see where a lot of variation is possible though the cultivars shown in OW are very white.
If cultural factors might change the result, you COULD try moving to California

I'd vote for genetic complexity, though...