Literate in listings does not work for every item

Question

I am reproducing C code style with listings. I have defined "" to be a string, so when I add libraries as "ff.h" it is treated as a string and is printed blue. To avoid that, I use literate.

An example of this:

\documentclass[11pt,fleqn]{article} 

\usepackage[dvipsnames]{xcolor} 

\usepackage{listings}

\lstdefinestyle{styleC}{
  language = C,
  commentstyle = {\color{ForestGreen}},
  stringstyle = {\color{NavyBlue}},
  comment = [l]{//},
  morecomment = [s]{/*}{*/},
  morestring = [b]',
  morestring = [b]",   
}

\lstnewenvironment{C}{
  \lstset{
    style=styleC,
    frame=single,
    literate = {"ff.h"}{"ff.h"}6 {"math.h"}{"math.h"}8 
    }
  }
  {}
  
  
\begin{document}
  
\begin{C}
#include <time.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <complex.h>
#include "ff.h"
#include "ffconf.h"
#include "math.h"
#include "arm_math.h"
#include "audioMoth.h"
\end{C}

\end{document}

with a correct result:

But when I applied this to all libraries:

literate = {"ff.h"}{"ff.h"}6 {"ffconf.h"}{"ffconf.h"}10 {"math.h"}{"math.h"}8   {"arm_math.h"}{"arm_math.h"}12 {"audioMoth.h"}{"audioMoth.h"}13 

the result is the following:

What could be happening?

Answer 1

You must use braces around the numbers if they get larger than 9:

\documentclass[11pt,fleqn]{article}

\usepackage[dvipsnames]{xcolor}

\usepackage{listings}

\lstdefinestyle{styleC}{
  language = C,
  commentstyle = {\color{ForestGreen}},
  stringstyle = {\color{NavyBlue}},
  comment = [l]{//},
  morecomment = [s]{/*}{*/},
  morestring = [b]',
  morestring = [b]",
}

\lstnewenvironment{C}{
  \lstset{
    style=styleC,
    frame=single,
    %literate = {"ff.h"}{"ff.h"}6 {"math.h"}{"math.h"}8
    literate = {"ff.h"}{"ff.h"}6 {"ffconf.h"}{"ffconf.h"}{10} {"math.h"}{"math.h"}8   {"arm_math.h"}{"arm\_math.h"}{12} {"audioMoth.h"}{"audioMoth.h"}{13}
    }
  }
  {}


\begin{document}

\begin{C}
#include <time.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <complex.h>
#include "ff.h"
#include "ffconf.h"
#include "math.h"
#include "arm_math.h"
#include "audioMoth.h"
\end{C}

\end{document}