[XeTeX] Diacritics in color (was Re: XETEX cannot access OpenType features in PUA?)

[Aleksandr Andreev]

Jonathan Kew writes:

>> Making this work in xetex would require a different approach to implementing color.

I have been able to get it to work (the base glyph in black and the
"diacritic" in red) in LuaTeX using the luacolor package.

Here's a minimal example:

\documentclass{minimal}
\usepackage{fontspec}
\usepackage{xcolor}
\usepackage{luacolor}

\newfontface\moo{MezenetsUnicode}

\begin{document}
\moo
\textcolor{red}{}
\end{document}

I'm not much of an expert in the inner workings of TeX and I know
absolutely nothing about Lua (is that a derivative of LISP?) so I
can't comment on whether the luacolor package could be ported to
XeTeX.

Any insights?

Aleks