code: public ColorPixel scale(double factor){
  		return setRGB_fromDouble_preserveAlpha(r_asDouble()*factor, g_asDouble()*factor, b_asDouble()*factor);
  	}
docs: Scales the RGB vector by the specified factor. Alpha is preserved.
  @param factor to scale the RGB channels with
  @return this pixel for chaining
  
  @see #scale(double)
  @see #normalize()
  @see #getLen()
  @see #getLenSquared()
  @see #add(double, double, double)
  @see #subtract(double, double, double)
  @see #cross(double, double, double)
  @see #cross_(double, double, double)
  @see #dot(double, double, double)
  @see #transform(double[][] mat)