Valiant - Color Changing SwimshortsValiant swimwear responds to temperature changes. So, these color changing swim trunks need warmth and cold to change color. When youre wearing these swim trunks, theyre (usually) warm due to your body heat and the warmth of the sun. To make your Valiant swim shorts change color, get cool! That means splash, jump or dive into the water and watch what happens. Size Chart: Size Waist (cm) Waist (in) Hips (cm) Hips (in) S 78 82 30. 7 32. 3 94 98 37. 0