FillRect doesn't paint the complete TStringGrid cell in Delphi

This is expected behaviour in Delphi when DefaultDrawing = true and themes are enabled.We can solve this issue in two ways,    1) Since we are drawing the grid cell ourself , so we need to turn off the grid property DefaultDrawing, set it to false.    2) A workaround is to check for this condition and decrement Rect.Left by 4 pixel before calling FillRect