ComboBox can't change background color items

Hi there, I saw @daniel post about the colour in the popupMenu. I am trying the same here.

I have a comboBox with different Items and I would like to change the background color of the items.

And I tried the code but I guess I am missing something. Here is @daniel code

Colour LookAndFeel::findPopupMenuColour (PopupMenu::ColourIDs colourId, const PopupMenu::Options& options)
    if (auto* target = options.getTargetComponent())
        return target->findColour (colourId);

    return findColour (colourId);

void LookAndFeel_V2::drawPopupMenuBackground (Graphics& g, int width, int height, const PopupMenu::Options& options)
    auto background = findPopupMenuColour (PopupMenu::backgroundColourId, options);
    // ...

I have changed the code in LookAndFeel_V2 but I am not sure whats next. I tried to send the component as an argument, but I can’t even call the function.

Thanks in advance