Highlighting specific parts of a customize graph

Question

I want to highlight specific parts, like this, for my graph (see code below). But in my case the highlighting (from the link above) doesn't work. The specific customized graph elements come from here.

\documentclass[border=5pt, xcolor=dvipsnames]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage[utf8x]{inputenc}
\usepackage{tikz}\usetikzlibrary{positioning,backgrounds,calc,trees,decorations.markings,automata,angles,quotes}

\tikzset{
    myneg/.style={
        decoration={
            markings,
            mark=at position 0.5 with 
                {\draw (0,0) arc (0:180:#1) (0,0) arc (180:360:#1);}
        },
        postaction=decorate
    },
    myneg/.default=6pt,
    mynode/.style={
        draw,
        circle,
        minimum size=20pt
    }
}

\pgfdeclarelayer{background}
\pgfsetlayers{background,main}

\newcommand{\convexpath}[2]{
[   
        create hullnodes/.code={
                \global\edef\namelist{#1}
                \foreach [count=\counter] \nodename in \namelist {
                        \global\edef\numberofnodes{\counter}
                        \node at (\nodename) [draw=none,name=hullnode\counter] {};
                }
                \node at (hullnode\numberofnodes) [name=hullnode0,draw=none] {};
                \pgfmathtruncatemacro\lastnumber{\numberofnodes+1}
                \node at (hullnode1) [name=hullnode\lastnumber,draw=none] {};
        },
        create hullnodes
]
($(hullnode1)!#2!-90:(hullnode0)$)
\foreach [
        evaluate=\currentnode as \previousnode using \currentnode-1,
        evaluate=\currentnode as \nextnode using \currentnode+1
        ] \currentnode in {1,...,\numberofnodes} {
-- ($(hullnode\currentnode)!#2!-90:(hullnode\previousnode)$)
    let \p1 = ($(hullnode\currentnode)!#2!-90:(hullnode\previousnode) - (hullnode\currentnode)$),
        \n1 = {atan2(\x1,\y1)},
        \p2 = ($(hullnode\currentnode)!#2!90:(hullnode\nextnode) - (hullnode\currentnode)$),
        \n2 = {atan2(\x2,\y2)},
        \n{delta} = {-Mod(\n1-\n2,360)}
    in 
        {arc [start angle=\n1, delta angle=\n{delta}, radius=#2]}
}
-- cycle
}

\begin{document}
\begin{tikzpicture}[node distance=1cm and 2cm]
\node[mynode, color=MidnightBlue] (b) at (0,0) {$U_3$};
\node[mynode,above=of b,color=MidnightBlue] (a) {$U_2$};
\node[mynode, above=of a,color=MidnightBlue] (h) {$U_1$};
\node[mynode,below=of b,color=MidnightBlue] (c) {$U_4$};
\node[mynode,right=of b] (d) {$$};
\node[mynode,right=of d,color=BrickRed] (e) {$W_2$};
\node[mynode,below=of e,color=BrickRed] (f) {$W_3$};
\node[mynode,above =of e, color=BrickRed] (j) {$W_1$};
\coordinate (aux) at (d.west);  
\foreach \Value in {a,b,c} 
    \draw (\Value) -- (aux);
\path 
    pic[draw,angle radius=35pt,"\raisebox{20pt}{$\lor$}",
        angle eccentricity=1.25] 
    {angle=a--aux--c}; 

\node[above left= -0.3 cm and  1 cm  of j,font=\scshape] {$\land$};

\draw
    (h) -- (j);
\draw[]
    (d) -- (e);
\draw[myneg]
    (c) -- (f);
\draw[myneg]
    (a) -- (j); 
\fill[red,opacity=0.3] \convexpath{h,a,j}{40pt};
\end{tikzpicture}
\end{document}

Below there is the code just for the graph, in which I want to highlight specific parts:

    \documentclass[border=5pt, xcolor=dvipsnames]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage[utf8x]{inputenc}

\usepackage{tikz}
\usetikzlibrary{positioning,decorations.markings,automata,angles,quotes}

\tikzset{
    myneg/.style={
        decoration={
            markings,
            mark=at position 0.5 with 
                {\draw (0,0) arc (0:180:#1) (0,0) arc (180:360:#1);}
        },
        postaction=decorate
    },
    myneg/.default=6pt,
    mynode/.style={
        draw,
        circle,
        minimum size=20pt
    }
}

\begin{document}

\begin{tikzpicture}[node distance=1cm and 2cm]
\node[mynode, color=MidnightBlue] (b) at (0,0) {$U_3$};
\node[mynode,above=of b,color=MidnightBlue] (a) {$U_2$};
\node[mynode, above=of a,color=MidnightBlue] (h) {$U_1$};
\node[mynode,below=of b,color=MidnightBlue] (c) {$U_4$};
\node[mynode,right=of b] (d) {$$};
\node[mynode,right=0cm and 4.5cm of b,color=BrickRed] (e) {$W_2$};
\node[mynode,right= 0cm and 4.5cm of c,color=BrickRed] (f) {$W_3$};
\node[mynode,right =0cm and 4.5cm of a, color=BrickRed] (j) {$W_1$};
\coordinate (aux) at (d.west);  
\foreach \Value in {a,b,c} 
    \draw (\Value) -- (aux);
\path 
    pic[draw,angle radius=35pt,"\raisebox{20pt}{$\lor$}",
        angle eccentricity=1.25] 
    {angle=a--aux--c}; 

\node[above left= -0.3 cm and  1 cm  of j,font=\scshape] {$\land$};

\draw
    (h) -- (j);

\draw[]
    (d) -- (e);
\draw[myneg]
    (c) -- (f);
\draw[myneg]
    (a) -- (j);


\end{tikzpicture}


\end{document}