//Base bar
DrawRect(
         BarPosition.x1,
         BarPosition.y1-y,
         BarPosition.x2,
         BarPosition.y2-y,
         BarsBorderColor,
         BarsBGColor
         );
//Used space bar         
DrawRect(
         BarPosition.x1+1,
         (BarPosition.y1+1)-y,
         BarPosition.x1+((100-(free_M2/(totalM2Space/100)))*(BarPosition.x2-BarPosition.x1)/100), 
         (BarPosition.y2-1)-y, 
         BarsUsedSpaceColor,
         BarsUsedSpaceColor
         );