How to draw a bitmap icon and set its color?

Hello,

I've been trying to add icons and change their colors but so far I have failed.

I've added the bitmap files of the icons in the drawables folder and added them also drawables.xml (<bitmap id="cals" filename="cals.png" />) when calling directly the file in the layout.xml file (<bitmap id="cals" x="center" y="315" filename="../drawables/cals.png" />) the image shown is white icon within a black square.

How can I properly set the color and add the icon? In which files should I add what and in which functions?