code: func (f *Fpdf) SetFillColor(r, g, b int) {
  	f.setFillColor(r, g, b)
  }
docs: // SetFillColor defines the color used for all filling operations (filled
  // rectangles and cell backgrounds). It is expressed in RGB components (0
  // -255). The method can be called before the first page is created and the
  // value is retained from page to page.