Pink Because of this, the pink triangle has become a symbol of the modern gay rights movement. The transition to pink as a sexually differentiating color for girls occurred gradually, through the selective process of the marketplace, in the 1930s and 40s. In the 1920s, some groups had been describing pink as a masculine color, an equivalent of the red that was considered to be for men, but lighter for boys. But stores nonetheless found that people were increasingly choosing to buy pink for girls, and blue for boys, until this became an accepted norm in the 1940s. In optics, the
Wythoff symbol and formula_7, represent the corners of the Schwarz triangle used in the construction, which are formula_8, formula_9 and formula_10 radians respectively. The triangle is also represented with the same numbers, written formula_11. The vertical bar in the symbol specifies a categorical position of the generator point within the fundamental triangle according to the following: In this notation the mirrors are labeled by the reflection-order of the opposite vertex. The formula_18 values are listed "before" the bar if the corresponding mirror is active. The one "impossible" symbol formula_19 implies the generator point is on all mirrors, which is only possible if