AlphaL<COLOR, ALPHA>
This function makes a color transparent. The ALPHA function specifies just how opaque it should be. If ALPHA is zero, the returned color will be 100% transparent. If Alpha is 32768, the returned color will be 100% opaque. Note that if COLOR is already transparent, it will be made more transparent. Example: If COLOR is 50% opaque, and ALPHA returns 16384, the result will be 25% opaque.