Tone down string literals just a little

This makes it easier to quickly separate the description strings from the rest of a, for example, component declaration.

mlsshared.sty

@@ -13,6 +13,7 @@
 \definecolor{keywordcolor1} {rgb}{0.07, 0.46, 0.00}
 \definecolor{keywordcolor3} {rgb}{0.00, 0.20, 0.47}
 \definecolor{commentcolor}  {rgb}{0.58, 0.13, 0.57}
+\definecolor{stringcolor}   {rgb}{0.15, 0.15, 0.15}
 
 % It would be nice to have comments set in normal variable-width font without any sort of
 % column alignment by the listsings.sty package, just like the comments look in the LaTeXML build.
@@ -159,7 +160,7 @@
   keywordstyle=[1]\color{keywordcolor1},
   keywordstyle=[2]\color{keywordcolor1}\bfseries,
   keywordstyle=[3]\color{keywordcolor3},
-  stringstyle=\color{black},     % string literal style
+  stringstyle=\color{stringcolor},
   language=[short]modelica,     % Language that will be used by default, in particluar by plain \lstinline.
   showstringspaces=false,
   frame=lrtb,