update docu, WIP

fontspec-doc-featset.tex

@@ -330,7 +330,7 @@ \subsection{Colour}
 (For example, if you set the colour in a \verb|\setmainfont| command, \verb|\color{...}| and related commands, including hyperlink colouring, will no longer have any effect on text in this font.)
 Therefore, \pkg{fontspec}'s colour commands are best used to set explicit colours in specific situations, and the \pkg{xcolor} package is recommended for more general colour functionality.
 
-The colour is defined as a triplet of two-digit Hex RGB
+The colour can be defined as a triplet of two-digit Hex RGB
 values, with optionally another value for the transparency (where
 |00| is completely transparent and |FF| is opaque.)
 \begin{Lexample}{color}{Selecting colour with transparency.}
@@ -341,8 +341,6 @@ \subsection{Colour}
   {\addfontfeature{Color=DDBB2299}P}\kern-0.5ex
   {\addfontfeature{Color=00BB3399}R}
 \end{Lexample}
-Transparency is supported by \LuaLaTeX; \XeLaTeX\ with the \texttt{xdvipdfmx} driver
-does not support this feature.
 
 If you load the \pkg{xcolor} package, you may use any named colour instead
 of writing the colours in hexadecimal.