We grow watermelons in the Leningrad region for only two years, the climate is not very favorable, but the greenhouse helps out very much! Now you will not be surprised by tomatoes of different colors, but watermelons are not inferior in any way to their variety!
Last year we had 11 yellow varieties, 4 orange, 3 white and 12 red.
Source - http://pikabu.ru/story/nashi_arbuzyi_v_leningradskoy_oblasti_4104026