PyQt changing QPushButton background color without resetting style

Question

I want to change a Button's background color and text color without changing/resetting the whole style.

Currently, I'm using this:

dl_btt.setStyleSheet("background-color: green; color: white")

But that changes the whole style of the button:

Since the default style looks like this:

I would like to have something like this:

So, if I were to change OS, I want it to use default style and only change the background color.

Can I do this without manually replicating the style?

EDIT:

@Controlix Thank you for pointing me in the right direction. However, I can't seem to be able to change the background color.

I'm only able to change the border and text color using:

dl_btt = DownloadButton(self, "Skini")

#dl_btt.setStyleSheet("background-color: green; color: white")
#dl_btt.setPalette(QtGui.QPalette(QtCore.Qt.green))

palette = dl_btt.palette()

role = dl_btt.foregroundRole()
palette.setColor(role, QtGui.QColor('white'))

role = dl_btt.backgroundRole()
palette.setColor(role, QtGui.QColor('green'))

dl_btt.setAutoFillBackground(True)
dl_btt.setPalette(palette)

Which gives me this result:

Searching gave me same or similar snippets of code that don't do what I expected it to do.

EDIT 2:

I gave up on this search and used style sheets, rebuilding the styles as I see fit.

I'm still wondering though... Is it possible, in PyQt, to replicate native style while changing only certain part of a widget?

EDIT 3

I tried:

    palette = dl_btt.palette()
    role = dl_btt.foregroundRole()
    palette.setColor(role, QtGui.QColor('white'))

    role = dl_btt.buttonRole()
    palette.setColor(role, QtGui.QColor('green'))

    dl_btt.setAutoFillBackground(True)
    dl_btt.setPalette(palette)

But I got this error:

AttributeError: 'DownloadButton' object has no attribute 'buttonRole'

How can I access the button role? How is it called?

Just in case you need it, here is the DownloadButton class:

class DownloadButton(QtGui.QPushButton):
    def __init__(self, master, *args, **kwargs):
        super(DownloadButton, self).__init__(*args, **kwargs)
        self.master = master

    def mousePressEvent(self, ev):
        self.master.startDownload()

Answer 1

I tried this which is working. I have set the buttons styles in the UI section. if I want to change only the color of a button the following works.

The following works though not an elegant way :

        btns = ['self.hBeamBtn','self.lBeamBtn','self.allTestBtn','self.prnStatusBtn']
        for btn in btns:
            if  str(btn_name) == str(btn):
                styl = btn+'.setStyleSheet("font: bold;background-color: red;font-size: 12px;height: 28px;width: 80px;")'
                eval(styl)

Answer 2

Here is a silly but working way to do it:

    def change_button_color(button, color):
        """change_button_color

            Change a button's color
        :param button: target button
        :type button: QPushButton
        :param color: new color (any format)
        :type color: str
        :return: None
        """
        style_sheet = button.styleSheet()
        pairs = [pair.replace(' ', '') for pair in style_sheet.split(';') if pair]

        style_dict = {}
        for pair in pairs:
            key, value = pair.split(':')
            style_dict[key] = value

        style_dict['background-color'] = color
        style_sheet = '{}'.format(style_dict)

        chars_to_remove = ('{', '}', '\'')
        for char in chars_to_remove:
            style_sheet = style_sheet.replace(char, '')
        style_sheet = style_sheet.replace(',', ';')

        button.setStyleSheet(style_sheet)

Answer 3

With this answer I managed to set the color of a button from a group to lightblue and reset the other not selected ones back to default.

Assuming that your main window stores the default palette, you can just access it and use it using self.palette().button().color() to set the color of your button to default again.

# Reset to default colors
for btn in self.btn_group.buttons():
    pal = btn.palette()
    pal.setColor(QPalette.Button, self.palette().button().color())
    btn.setPalette(pal)
    btn.update()
        
# Except for selected button
btn = self.btn_group.checkedButton()
pal = btn.palette()
pal.setColor(QPalette.Button, QColor.fromRgb(173, 216, 230))
btn.setPalette(pal)
btn.update()