How to format color bar for subplots

[munal]

I’m having a hard time getting a pretty color bar position and size for my plotly subplots. Each subplot is an overlay of scatter and line plots and a 2D histogram as the contours. I can either get no color bar or something that overlaps with the legends. How can I make it one color bar, small enough to fit under the legends on the right hand side of the canvas?

Here is my code block - I commented out my failed attempts

n_time_points = len(df_all[df_all['time-point'] < 20]['time-point'].unique())
    n_rows = (n_time_points + 1) // 2  # Add 1 and floor division to get even number of rows

    # Create a subplot with a 2xN layout
    row_width = [1.0] * n_rows
    column_width = [0.5] * 2
    fig = make_subplots(
        rows=n_rows,
        cols=2,
        subplot_titles=[f'Time-Point {i}' for i in range(n_time_points)],
        row_width=row_width,
        column_width=column_width
    )

    row, col = 1, 1  # Start with the first subplot
    for time_point, data in df_all[df_all['time-point'] < 20].groupby('time-point'):
        # Create your scatter plots and add them to the subplot grid
        trace_scatter = go.Scatter(
            x=df_com_filter[df_com_filter['time-point'] == time_point]['x'],
            y=df_com_filter[df_com_filter['time-point'] == time_point]['y'],
            mode='markers',
            marker=dict(color='red', size=5, opacity=1.0),
            name=f'CoM Time-Point {time_point}'
        )

        trace_shortest_path = go.Scatter(
            x=df_shortest_paths[df_shortest_paths['time-point'] == time_point]['x'],
            y=df_shortest_paths[df_shortest_paths['time-point'] == time_point]['y'],
            mode='lines',
            line=dict(color='blue', width=2),
            opacity=0.5,
            name=f'Shortest Path TP={time_point}'
        )

        trace_contour_data = go.Histogram2d(
            x=df_all[df_all['time-point'] == time_point]['x'],
            y=df_all[df_all['time-point'] == time_point]['y'],
            colorscale='Greys',  # Color scale
            #showscale=False,  # Show color scale
        )

        # colorbar_trace = go.Scatter(
        #     x=[],
        #     y=[],
        #     mode='markers',
        #     marker=dict(
        #         colorscale='Greys',
        #         colorbar=dict(
        #             x=1.1,     # X position (1.05 places it to the right of the plot)
        #             y=0.2,      # Y position (0.2 places it lower on the plot)
        #             len=0.01,    # Length (0.4 makes it shorter)
        #             thickness=10,  # Thickness (20 adjusts the width of the color bar)
        #         ),
        #     )
        # )

        fig.update_traces(
            colorbar_len=0.1, selector=dict(type='histogram2d')

        )

        fig.add_trace(trace_scatter, row=row, col=col)
        fig.add_trace(trace_shortest_path, row=row, col=col)
        fig.add_trace(trace_contour_data, row=row, col=col)
        # fig.add_trace(colorbar_trace, row=row, col=col)

        fig.update_xaxes(title_text='X Axis', row=row, col=col)
        fig.update_yaxes(title_text='Y Axis', row=1, col=1)

        col += 1
        if col > 2:
            col = 1
            row += 1

    fig.update_layout(
    title_text=canvas_title,
    title_x=0.1,  # Center the title horizontally
    title_y=0.99,  # Adjust the vertical position of the title
    title_font=dict(size=24),  # Set the font size
    )
    # Show the subplots
    fig.update_layout(height=2500, width=1000)
    fig.show()

Edit: I just realized that the color densities are not matching between subplots. If a common color density is not possible or hard to achieve, individual color bars is also ok as long as they can be small enough to fit near each plot.

Edit 2: When I try adding color bars as traces, I got the following (even worse, removing rest of the data)

        colorbar_trace = go.Scatter(
            x=[0.05],  # Adjust the x-coordinate for position
            y=[0.1],   # Adjust the y-coordinate for position
            mode='markers',
            marker=dict(
                colorscale='Greys',
                colorbar=dict(
                    len=0.1
                ),
            )
        )
        fig.add_trace(colorbar_trace, row=row, col=col)