(ups sorry not used to chats) the code is: \documentclass[tikz,12pt]{standalone}
\usetikzlibrary{hobby}
\begin{document}
\begin{tikzpicture}
\path [draw=red] (0,0) coordinate (f) to[curve through={+(.125,-.5) +(-.5,-1) +(0,-1.5) +(.5,-.75) }, save Hobby path={ff1}] (f);
\path [draw=blue,xshift=1mm] (f) [restore and use Hobby path={ff1}{}];
\path [draw=gray,xshift=-1.5mm] (f) [restore and use Hobby path={ff1}{}];
\end{tikzpicture}
\end{document}