code: private static double hslaHue(double h, double m1, double m2) {
          h = h < 0 ? h + 1 : (h > 1 ? h - 1 : h);
          if      (h * 6 < 1) { return m1 + (m2 - m1) * h * 6; }
          else if (h * 2 < 1) { return m2; }
          else if (h * 3 < 2) { return m1 + (m2 - m1) * (2F/3 - h) * 6; }
          else                { return m1; }
      }
docs: Calculate a single color channel of the HSLA function
  @param h hue value
  @param m1 value 1 in range of 0.0 to 1.0
  @param m2 value 2 in range of 0.0 to 1.0
  @return channel value in range of 0.0 to 1.0