code: func bgraModel(c color.Color) color.Color {
  	if _, ok := c.(BGRA); ok {
  		return c
  	}
  
  	r, g, b, a := c.RGBA()
  	return BGRA{
  		B: uint8(b >> 8),
  		G: uint8(g >> 8),
  		R: uint8(r >> 8),
  		A: uint8(a >> 8),
  	}
  }
docs: // bgraModel converts from any color to a BGRA color type.