[luatex] How to color unicode combinging characters.

[Philipp Stephani]

Am 18.03.2011 02:39, schrieb Khaled Hosny:
> On Thu, Mar 17, 2011 at 10:25:11PM +0200, Simo Ojala wrote:
>>
>> Hi,
>>
>> I am really just taking my first steps in TeX world, so forgive me
>> my ignorance. However I already have this quite advanced coloring
>> problem and I have read and been told that LuaTeX might be able to
>> solve this kind of stuff. So thats why I try to ask this here,
>> hopefully found the right place to post this kind of problem...
>>
>> I am trying to create some ancient hebrew inflection charts and the
>> problem is to be able to paint vowels (and other diacritics) without
>> changing color of the consonants they are combined with. (The vowels
>> are unicode combining characters which are positioned according to
>> and combined with consonants.) I already have got some suggestions
>> that I could do some thing like this:
>>
>> \textcolor{red}{a}\textcolor{blue}{b} % where 'a' represents a
>> consonant and 'b' a vowel
>>
>> However this leads to situation where the characters are not
>> actually combined, but just placed separately to the document. That
>> it turn leads to positioning problems and other bad stuff.
> 
> You don't provide any sample files, so one can only guess.

See the answer to the tex.sx question. I tried to provide an example,
and the coloring itself does work, but the marks are positioned
incorrectly and the text direction is wrong.