Glossary link's color

Normally the link color is set via the option linkcolor of the package hyperref. To influence only the link color of glossaries you must redefine the command \glstextformat. In the documentation you can find:

The way the link text is displayed depends on

\glstextformat{⟨text⟩}

For example, to make all link text appear in a sans-serif font, do:

\renewcommand*{\glstextformat}[1]{\textsf{#1}}

In relation to this comment here an example:

\documentclass[10pt,a4paper]{report}
\usepackage{xcolor}
\usepackage[colorlinks=true]{hyperref}
\usepackage[xindy]{glossaries}
\renewcommand*{\glstextformat}[1]{\textcolor{green}{#1}}

\makeglossaries
\newglossaryentry{A}{name={A}, description={A is A}}
\newglossaryentry{AA}{name={AA}, description={AA is AA}}
\newglossaryentry{B}{name={B}, description={B is B}}
\newglossaryentry{C}{name={C}, description={C is C}}
\newglossaryentry{CC}{name={CC}, description={CC is CC}}

\begin{document}
Here I cite either \gls{A}, \gls{AA}, \gls{B}, \gls{C} or \gls{CC}.
I want three groups in the glossary output, indicated by \textbf{A},
\textbf{B} and \textbf{C} with entries in them according to their initial letter.

\printglossary[style=indexgroup]
\end{document}

I had a similar request, with the only difference that I didn't want to have any colored glossary links at all. Marco's solution wasn't satisfying for me as it changes all links to a specific color. Instead I wanted to keep the corresponding current text color.

---

Another approach might be setting the hyperlink color to the current text color (.) before the hyperlink is created and resetting it to the globally used link color (\@linkcolor) afterwards in a new command:

\newcommand*{\glsplainhyperlink}[2]{%
  \colorlet{currenttext}{.}% store current text color
  \colorlet{currentlink}{\@linkcolor}% store current link color
  \hypersetup{linkcolor=currenttext}% set link color
  \hyperlink{#1}{#2}%
  \hypersetup{linkcolor=currentlink}% reset to default
}

Then, override the existing \@glslink to use our command:

\let\@glslink\glsplainhyperlink

---

Complete example with a black link on white background and a white link on a black background:

\documentclass{report}
\usepackage{xcolor}
\usepackage[colorlinks,linkcolor=green]{hyperref}
\usepackage{glossaries}

\makeatletter
\newcommand*{\glsplainhyperlink}[2]{%
  \colorlet{currenttext}{.}% store current text color
  \colorlet{currentlink}{\@linkcolor}% store current link color
  \hypersetup{linkcolor=currenttext}% set link color
  \hyperlink{#1}{#2}%
  \hypersetup{linkcolor=currentlink}% reset to default
}
\let\@glslink\glsplainhyperlink
\makeatother

\makenoidxglossaries
\newglossaryentry{GPU}{name={GPU}, description={Graphics Processing Unit}}

\begin{document}

  I need a faster \gls{GPU}.

  \colorbox{black}{\color{white}I need a faster \gls{GPU}.}

  \printnoidxglossary

\end{document}