Use the given cmap to color the bars, applying the correct
        color ranges as necessary.

def _colorize_bars(self, cmap, bars, element, main_range, dim):
        """
        Use the given cmap to color the bars, applying the correct
        color ranges as necessary.
        """
        cmap_range = main_range[1] - main_range[0]
        lower_bound = main_range[0]
        colors = np.array(element.dimension_values(dim))
        colors = (colors - lower_bound) / (cmap_range)
        for c, bar in zip(colors, bars):
            bar.set_facecolor(cmap(c))
            bar.set_clip_on(False)