Solid Washed Water Repellent Swim Trunks

Found these for a super great sale price and size options were limited. We ordered a size large for my husband in one color (red) and size medium in the blue color. Oddly, both pair fit and he kept both. I’m not sure how to account for the size discrepancy - maybe one color runs larger or smaller than another color? Or there’s just enough give in the style that medium or large would both work? Either way, he loved them both.