How to use the silx.gui.qt.QColor function in silx

def _updatePrinter(self):
        """Resize :attr:`page`, :attr:`scene` and :attr:`view` to :attr:`printer`
        width and height."""
        printer = self.printer
        assert printer is not None, \
            "_updatePrinter should not be called unless a printer is defined"
        if self.scene is None:
            self.scene = qt.QGraphicsScene()
            self.scene.setBackgroundBrush(qt.QColor(qt.Qt.lightGray))
            self.scene.setSceneRect(qt.QRectF(0, 0, printer.width(), printer.height()))

        if self.page is None:
            self.page = qt.QGraphicsRectItem(0, 0, printer.width(), printer.height())
            self.page.setBrush(qt.QColor(qt.Qt.white))
            self.scene.addItem(self.page)

        self.scene.setSceneRect(qt.QRectF(0, 0, printer.width(), printer.height()))
        self.page.setPos(qt.QPointF(0.0, 0.0))
        self.page.setRect(qt.QRectF(0, 0, printer.width(), printer.height()))

        if self.view is None:
            self.view = qt.QGraphicsView(self.scene)
            self.mainLayout.addWidget(self.view)
            self._buildStatusBar()
        # self.view.scale(1./self._viewScale, 1./self._viewScale)
        self.view.fitInView(self.page.rect(), qt.Qt.KeepAspectRatio)
        self._viewScale = 1.00
        self._updateTargetLabel()

itemId = matchDict['itemId']

            # TODO : delegate the deserialization to the serialized items
            if itemId == 'IsoSurfaces':
                argsMatch = isoSurfaceArgsRegex.match(matchDict['args'])
                if not argsMatch:
                    # TODO : explicit error
                    raise ValueError('Failed to parse args "{0}".'
                                     ''.format(matchDict['args']))
                argsDict = argsMatch.groupdict()
                nIso = int(argsDict['nIso'])
                if nIso:
                    for surface in self.getIsosurfaces():
                        self.removeIsosurface(surface)
                    for isoIdx in range(nIso):
                        color = qt.QColor()
                        stream >> color
                        level = stream.readDouble()
                        visible = stream.readBool()
                        surface = self.addIsosurface(level, color=color)
                        surface.setVisible(visible)
            elif itemId == 'Style':
                background = qt.QColor()
                foreground = qt.QColor()
                highlight = qt.QColor()
                stream >> background >> foreground >> highlight
                self.setBackgroundColor(background)
                self.setForegroundColor(foreground)
                self.setHighlightColor(highlight)
            else:
                raise ValueError('Unknown entry tag {0}.'
                                 ''.format(itemId))

def getColor(self):
        """Returns the color used for the profile and ROI

        :rtype: QColor
        """
        return qt.QColor.fromRgbF(*self._color)

''.format(matchDict['args']))
                argsDict = argsMatch.groupdict()
                nIso = int(argsDict['nIso'])
                if nIso:
                    for surface in self.getIsosurfaces():
                        self.removeIsosurface(surface)
                    for isoIdx in range(nIso):
                        color = qt.QColor()
                        stream >> color
                        level = stream.readDouble()
                        visible = stream.readBool()
                        surface = self.addIsosurface(level, color=color)
                        surface.setVisible(visible)
            elif itemId == 'Style':
                background = qt.QColor()
                foreground = qt.QColor()
                highlight = qt.QColor()
                stream >> background >> foreground >> highlight
                self.setBackgroundColor(background)
                self.setForegroundColor(foreground)
                self.setHighlightColor(highlight)
            else:
                raise ValueError('Unknown entry tag {0}.'
                                 ''.format(itemId))

def markerColorList(self):
        colormap = self.getRawColormap()
        name = colormap['name']
        if name not in self.__markerColors:
            style = self.getCurrentStyle()
            if "markers" in style:
                colors = []
                for c in style["markers"]:
                    c = qt.QColor(c[0], c[1], c[2])
                    colors.append(c)
            else:
                colors = self.createMarkerColors()
            self.__markerColors[name] = colors
        else:
            colors = self.__markerColors[name]
        return colors

r, g, b = self._fgcolors[selection][0:3]
                    if self._fgcolors.shape[-1] == 3:
                        return qt.QColor(r, g, b)
                    if self._fgcolors.shape[-1] == 4:
                        a = self._fgcolors[selection][3]
                        return qt.QColor(r, g, b, a)

                # no fg color given, use black or white
                # based on luminosity threshold
                elif self._bgcolors is not None:
                    r, g, b = self._bgcolors[selection][0:3]
                    lum = 0.21 * r + 0.72 * g + 0.07 * b
                    if lum < 128:
                        return qt.QColor(qt.Qt.white)
                    else:
                        return qt.QColor(qt.Qt.black)

def disabledMarkerColor(self):
        style = self.getCurrentStyle()
        color = style.get("disabled-marker", None)
        if color is None:
            color = [128, 128, 128]
        return qt.QColor(*color)

def icon(self):
        pixmap = qt.QPixmap(2, 2)
        painter = qt.QPainter(pixmap)
        painter.setPen(qt.QColor(255, 0, 0))
        painter.drawPoint(qt.QPoint(0, 0))
        painter.setPen(qt.QColor(255, 255, 0))
        painter.drawPoint(qt.QPoint(1, 0))
        painter.setPen(qt.QColor(0, 255, 0))
        painter.drawPoint(qt.QPoint(0, 1))
        painter.setPen(qt.QColor(0, 255, 255))
        painter.drawPoint(qt.QPoint(1, 1))
        painter.end()
        pixmap = pixmap.scaled(32, 32, qt.Qt.IgnoreAspectRatio, qt.Qt.FastTransformation)
        return qt.QIcon(pixmap)

def _updateColorGradient(self):
        """Compute the color gradient"""
        colormap = self.getColormap()
        if colormap is None:
            return

        indices = numpy.linspace(0., 1., self._NB_CONTROL_POINTS)
        colors = colormap.getNColors(nbColors=self._NB_CONTROL_POINTS)
        self._gradient = qt.QLinearGradient(0, 1, 0, 0)
        self._gradient.setCoordinateMode(qt.QGradient.StretchToDeviceMode)
        self._gradient.setStops(
            [(i, qt.QColor(*color)) for i, color in zip(indices, colors)]
        )

def getForegroundColor(self):
        """Return color used for bounding box

        :rtype: QColor
        """
        return qt.QColor.fromRgbF(*self._foregroundColor)