请问，这种带自定义函数(是这么叫的吗)，是如何写出的？我应该在哪儿学习？

\def{\cR}{FE4C61} \def{\cO}{F39C11} \def{\cY}{FFC116} \def{\cG}{52C41A} \def{\cB}{3498DB} \def{\cP}{9D3DCF} \def{\cD}{0E1D69} \def{\cE}{BFBFBF} \def{\s}{35pt} \def{\w}{\kern{5pt}}
\newcommand{\a}[1]{&\textcolor{A9A9A9}{\kern{-5pt}\underline{#1\kern{242pt}}\kern{8pt}}\\[\s]}
\newcommand{\b}[2]{\fcolorbox{black}{#2}{\raisebox{#1pt}{\kern{10pt}}}\raisebox{#1pt}{\scriptsize\kern{-17pt}\raisebox{4.5pt}{#1题}}}
\newcommand{\c}[0]{\kern{-10pt}\large\textbf{通过难度统计表}}
\newcommand{\t}[2]{\fcolorbox{black}{#2}{\color{white}\textbf{#1}}}
\newcommand{\main}[9]{
\boxed{\kern{8pt}\begin{gathered}\\[-6pt]\c\\[10pt]
\begin{aligned}\a{50}\a{\w0}\end{aligned} \\[-64pt] \\[-#1pt]
\begin{matrix}
 & \b{#2}{\cE}& \b{#3}{\cR} & \b{#4}{\cO} & \b{#5}{\cY} & \b{#6}{\cG} & \b{#7}{\cB} & \b{#8}{\cP} & \b{#9}{\cD} & \\[5pt]
\kern{-6pt}\text{项目} & \t{灰}{\cE} & \t{红}{\cR} & \t{橙}{\cO} & \t{黄}{\cY}&\t{绿}{\cG}&\t{蓝}{\cB}&\t{紫}{\cP} & \t{黑}{\cD} & \kern{8pt} \\
\end{matrix}
\end{gathered}}}
\main{48}{0}{18}{48}{31}{24}{23}{6}{0}

main中有输入。