title: Convert ARGB to RGB without losing information
body: <p>i try to convert a argb value to a rgb-value without losing the information it got from his background. 
  so for example: the background is black, the argb is (150,255,0,0) and as the result i wan't to have a kind of brown.</p>
  
  <p>is there any chance to deal with that?</p>