A nice type of footnote

Question

In relation to the question A nice collection of exercises for students that I have asked, at the moment I do not know how to have the same shaded line inverted in gray (I would to have the possibility to change the color: for example orange, or other colors) at the top right that can be replaced instead of the classic horizontal black line of the \footnote command.

See the picture below in attachment:

Here there is my output and my MWE:

\documentclass[12pt]{article}
\usepackage[bottom,hang]{footmisc}
\setlength\footnotemargin{4.5pt}
\setlength{\footnotesep}{4.5pt}
\setlength{\skip\footins}{8mm}
\begin{document}
First word\footnote{One}, Second word\footnote{Two}
\end{document}

Answer 1

Just \renewcommand\footnoterule using the (simplified) definition of the rule in the linked post. You have to do this before loading the package footmisc because it overwrites \footnoterule.

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{fadings}

\renewcommand\footnoterule{%
  \noindent
  \kern-3pt
  \begin{tikzpicture}[baseline=-10pt]
    \fill[darkgray,path fading=east] (0,0) rectangle (.4\columnwidth,0.02);
  \end{tikzpicture}%
  \kern2.6pt
}

\usepackage[bottom,hang]{footmisc}
\setlength\footnotemargin{4.5pt}
\setlength{\footnotesep}{4.5pt}
\setlength{\skip\footins}{8mm}
\begin{document}
First word\footnote{One}, Second word\footnote{Two}
\end{document}

Answer 2

[EDIT: This answer does not change the footnote rule, but only change the footnote text and symbol colors]

Adding 3 lines into your preamble may give you what you want:

\documentclass[12pt]{article}
\usepackage[bottom,hang]{footmisc}
\setlength\footnotemargin{4.5pt}
\setlength{\footnotesep}{4.5pt}
\setlength{\skip\footins}{8mm}
%
\usepackage{xcolor}
\renewcommand{\thefootnote}{\color{orange}\arabic{footnote}} % change the color of the footnote counter
\renewcommand{\footnotelayout}{\color{orange}} % change the color of the footnote text
%
\begin{document}
First word\footnote{One}, Second word\footnote{Two}.
\end{document}

The output would be: