Modifying the multiple letters macro \FormatChars

Question

Regarding the multiple letters macro "\FormatChars" posted in Emphasizing Arabic text characters. Is there a way to modify this macro such that:

• You can select any set of characters you want to modify despite of their arrangement within the word, I have noticed that you can only select a consecutive set of letters (so you select letters from 1 till 3, 2 till 4...) yet there is a need to select non-consecutive characters within the same word (the first and third letters for example, or second and fifth letter...etc)

• Set the formatting to be applied for each of the selected characters seperately so that a different type of formatting can be applied to each of the selected characters instead of applying the same formatting to all of the specified characters.

Answer 1

You can use lua-ul package which highlight or underline letters of word without breaking ligatures, kerning, font shaping.

You can also create your own format of underlining with \newunderlinetype.

\documentclass{article}
\usepackage[bidi=basic]{babel}
\babelprovide[import,main]{arabic}
\babelfont{rm}{Amiri}
\usepackage{luacolor,lua-ul}
\begin{document}
\Huge
\highLight[red]{ج}\underLine{نو}\highLight[yellow]{ب} \quad
\textcolor{red}{ج}\underLine{نو}\textcolor{blue}{ب} \quad
\underLine{\textcolor{red}{ج}نو}\highLight[green]{\textcolor{red}{ب}} \quad
% Coloring diacritical marks
ج%
\textcolor{blue}{َ}% fatha
نوب%
\textcolor{red}{ٌ}% tanween
\end{document}