How to use the xlsxwriter.utility.get_rgb_color function in XlsxWriter

# Write the a:xfrm element.
        self._write_a_xfrm(col_absolute, row_absolute, width, height, shape)

        # Write the a:prstGeom element.
        self._write_a_prst_geom(shape)

        if shape.fill:
            if not shape.fill['defined']:
                # Write the a:solidFill element.
                self._write_a_solid_fill_scheme('lt1')
            elif 'none' in shape.fill:
                # Write the a:noFill element.
                self._xml_empty_tag('a:noFill')
            elif 'color' in shape.fill:
                # Write the a:solidFill element.
                self._write_a_solid_fill(get_rgb_color(shape.fill['color']))

        if shape.gradient:
            # Write the a:gradFill element.
            self._write_a_grad_fill(shape.gradient)

        # Write the a:ln element.
        self._write_a_ln(shape.line)

        self._xml_end_tag('xdr:spPr')

def _write_a_gs_lst(self, gradient):
        # Write the  element.
        positions = gradient['positions']
        colors = gradient['colors']

        self._xml_start_tag('a:gsLst')

        for i in range(len(colors)):
            pos = int(positions[i] * 1000)
            attributes = [('pos', pos)]
            self._xml_start_tag('a:gs', attributes)

            # Write the a:srgbClr element.
            # TODO: Wait for a feature request to support transparency.
            color = get_rgb_color(colors[i])
            self._write_a_srgb_clr(color)

            self._xml_end_tag('a:gs')

        self._xml_end_tag('a:gsLst')

def _write_a_solid_fill(self, fill):
        # Write the  element.

        self._xml_start_tag('a:solidFill')

        if 'color' in fill:
            color = get_rgb_color(fill['color'])
            transparency = fill.get('transparency')
            # Write the a:srgbClr element.
            self._write_a_srgb_clr(color, transparency)

        self._xml_end_tag('a:solidFill')

def _write_a_bg_clr(self, color):
        # Write the  element.

        color = get_rgb_color(color)

        self._xml_start_tag('a:bgClr')

        # Write the a:srgbClr element.
        self._write_a_srgb_clr(color)

        self._xml_end_tag('a:bgClr')

def _write_a_fg_clr(self, color):
        # Write the  element.

        color = get_rgb_color(color)

        self._xml_start_tag('a:fgClr')

        # Write the a:srgbClr element.
        self._write_a_srgb_clr(color)

        self._xml_end_tag('a:fgClr')

def _write_a_gs_lst(self, gradient):
        # Write the  element.
        positions = gradient['positions']
        colors = gradient['colors']

        self._xml_start_tag('a:gsLst')

        for i in range(len(colors)):
            pos = int(positions[i] * 1000)
            attributes = [('pos', pos)]
            self._xml_start_tag('a:gs', attributes)

            # Write the a:srgbClr element.
            # TODO: Wait for a feature request to support transparency.
            color = get_rgb_color(colors[i])
            self._write_a_srgb_clr(color)

            self._xml_end_tag('a:gs')

        self._xml_end_tag('a:gsLst')