Sideband/sbapp/kivymd/uix/card/card.kv

<MDCardSwipeLayerBox>:
    md_bg_color: app.theme_cls.divider_color


<MDCard>
    canvas.before:
        Color:
            rgba: self.md_bg_color
        RoundedRectangle:
            size: self.size
            pos: self.pos
            radius: root.radius
            source: root.background


<MDSeparator>
    md_bg_color:
        self.theme_cls.divider_color \
        if not root.color \
        else root.color