Colorbar based on line width or color

[prameshk]

Is it possible to create a color bar, that tells the range of line width values? Similarly, it would be nice to have an option that outputs colorbar based on the intensity of colors. These will be important features for creating network-based heatmaps.

\begin{tikzpicture}
\Vertices{data/vertices.csv}
\Edges[Direct]{data/edges.csv}
\end{tikzpicture}