https://web2.0calc.com/questions/cool-rainbow-latex
\color{red}{\LaTeX}_{\color{orange}{\LaTeX}_{\color{green}{\LaTeX}}{\color{blue}{\LaTeX}}}^{\color{orange}{\LaTeX}^{\color{green}{\LaTeX}}{\color{blue}{\LaTeX}}}\color{purple}{\LaTeX}
\(\color{red}{\LaTeX}_{\color{orange}{\LaTeX}_{\color{green}{\LaTeX}}{\color{blue}{\LaTeX}}}^{\color{orange}{\LaTeX}^{\color{green}{\LaTeX}}{\color{blue}{\LaTeX}}}\color{purple}{\LaTeX}\)
.