show me 3 or upper method to change a qt gui push button color to red when it is pressed in gnuradio 3.8 grc

Here are three methods to change the color of a QPushButton in a Qt GUI when it is pressed in GNU Radio 3.8 GRC:

Method 1: Using Qt Style Sheets

1. Select the QPushButton in the Qt Designer.
2. Go to the "Property Editor" tab.
3. Click on the "Style Sheet" property and enter the following code:

QPushButton:pressed {
    background-color: red;
}

This will change the background color of the QPushButton to red when it is pressed.

Method 2: Using PyQt5 Signals and Slots

1. In the GRC flowgraph, add a "QT GUI Push Button" block.
2. Open the "Edit Properties" dialog for the block.
3. In the "Signals" tab, add a new signal for "pressed()" and connect it to a new slot.
4. In the "Slots" tab, add a new slot and enter the following code:

self.button.setStyleSheet("background-color: red")

This will change the background color of the QPushButton to red when it is pressed.

Method 3: Using Python Callbacks

1. In the GRC flowgraph, add a "QT GUI Push Button" block.
2. Open the "Edit Properties" dialog for the block.
3. In the "Callbacks" tab, add a new callback for "pressed()" and select "Python" as the language.
4. In the "Code" field, enter the following code:

self.button.setStyleSheet("background-color: red")

This will change the background color of the QPushButton to red when it is pressed.