LaTeX: To use color variable fonts with LuaLaTeX

scvarsnowman.tex

%#!lualatex
\documentclass{article}
\usepackage[a6paper, scale=0.88]{geometry}
\usepackage{fontspec}
% Font available at https://github.com/zr-tex8r/SCVarSnowman
\newfontface\fSCVS{SCVarSnowman.ttf}[Renderer=HarfBuzz]
\newcommand*{\cItem}[1]{%
  \item \makebox[5em][l]{\ttfamily MOOD=#1}%
    % 'MOOD' axis: +100=smiling .. 0=neutral .. -100=frowning
    {\fSCVS\addfontfeatures{RawFeature={+axis={MOOD=#1}}}%
      \LARGE ☃⛄%                   with a red muffler
      {\addfontfeatures{StylisticSet=3}☃⛄}% ss03 green
      {\addfontfeatures{StylisticSet=4}☃⛄}% ss04 blue
      {\addfontfeatures{StylisticSet=5}☃⛄}% ss05 yellow
      {\addfontfeatures{StylisticSet=6}☃⛄}}%ss06 purple
}
\begin{document}
\begin{itemize}
\cItem{-100}
\cItem{-50}
\cItem{0}
\cItem{50}
\cItem{100}
\end{itemize}
\end{document}

The font “SCVarSnowman” is available at GitHub.