I need to redefine "\citet" command to have its output printed in red. I did:
\let\oldcitet\citet
\renewcommand*\citet[2][]{{\color{red}\oldcitet[#1]{#2}}}
that works for the "one optional argument" case: \citet[ARG]{label}
.
How can I get the same result for the "two optional argument" case: \citet[ARG1][ARG2]{label}
?