Square root of color sounds like gamma encoding. He had a linear color, and wants to store it as sRGB; raising it to 1/2.2 is "correct" but sqrt is close enough

Square root of color sounds like gamma encoding. He had a linear color, and wants to store it as sRGB; raising it to 1/2.2 is "correct" but sqrt is close enough. (Or it's just for tone mapping.)