code: public void setDecorationBackgroundColor(Color decorationBackgroundColor) {
  		this.decorationBackgroundColor = decorationBackgroundColor;
  
  		if (days != null) {
  			for (int i = 0; i < 7; i++) {
  				days[i].setBackground(decorationBackgroundColor);
  			}
  		}
  
  		if (weeks != null) {
  			for (int i = 0; i < 7; i++) {
  				weeks[i].setBackground(decorationBackgroundColor);
  			}
  		}
  	}
docs: Sets the background of days and weeks of year buttons.
  
  @param decorationBackgroundColor
  The background to set