How to use the xterm/src/common/buffer/AttributeData.AttributeData.toColorRGB function in xterm

private getHexColor (mode: number, color: number, def: string): string {
        if (mode === Attributes.CM_RGB) {
            const rgb = AttributeData.toColorRGB(color)
            return rgb.map(x => x.toString(16).padStart(2, '0')).join('')
        }
        if (mode === Attributes.CM_P16 || mode === Attributes.CM_P256) {
            return this.configService.store.terminal.colorScheme.colors[color]
        }
        return def
    }