static RGB fixRGB(RGB rgb) {
  ret rgb == null ? null : RGB(limitBetween0and1(rgb.r), limitBetween0and1(rgb.g), limitBetween0and1(rgb.b));
}

static RGB fixRGB(float r, float g, float b) {
  ret RGB(limitBetween0and1(r), limitBetween0and1(g), limitBetween0and1(b));
}