[Tex/LaTex] how to change the color of the rule (vertical line) in twocolumn document

colormulticolrulestwo-column

I'd like to make the rule between the 2 columns very thin. I found that no matter how small of width I made it, the line was not thin enough for my liking (unless I make it zero, then it will disappear)

So I thought may be if I change its color to say gray or light gray, that will make it appear very thin.

I can change the width of the rule, but not its color:

enter image description here

Do I have to include multicol package for this? but when I tried

\documentclass[twocolumn]{article}%
\usepackage{lipsum}
\usepackage{multicol}
\usepackage{color}
\setlength{\columnseprule}{0.00001pt}
\def\columnseprulecolor{\color{0.5,0.5,0.5}}%
\begin{document}   
\lipsum[1-5]
\end{document}

I see no change in the color. no matter what value I used. I must not be setting the columnseprulecolor correctly.

Also tried

\documentclass[twocolumn]{article}%
\usepackage{lipsum}
\usepackage{multicol}
\usepackage{color}
\setlength{\columnseprule}{1pt}
\def\columnseprulecolor{\color{red}}
\begin{document}   

\lipsum[1-5]
\end{document}

and few other things. So I give up.

How to change the color of the rule in twocolumn document?

update

Thanks to everyone for the answers. now it looks much better, now the line appears much thinner.

enter image description here

\documentclass{article}%
\usepackage{lipsum}
\usepackage{multicol}
\usepackage{color}
\setlength{\columnsep}{20pt}
\setlength{\columnseprule}{0.01pt}
\renewcommand{\columnseprulecolor}{\color[rgb]{0.9,0.9,0.9}}

\begin{document}
\begin{multicols}{2}
\lipsum[1-5]
\end{multicols}
\end{document}

Best Answer

Package multicol

\columnseprule only works inside environment multicols:

\documentclass{article}%
\usepackage{lipsum}
\usepackage{multicol}
\usepackage{color}
\setlength{\columnseprule}{1pt}
\renewcommand{\columnseprulecolor}{\color{red}}
\begin{document}
\begin{multicols}{2}
\lipsum[1-5]
\end{multicols}
\end{document}

Result

LaTeX without package multicol

The rule can also be colorized without package multicol. Then \@outputdlbcol needs to be patched:

\documentclass[twocolumn]{article}%
\usepackage{lipsum}
\usepackage{color}
\setlength{\columnseprule}{1pt}
\newcommand{\latexcolumnseprulecolor}{\color{red}}

\usepackage{etoolbox}
\makeatletter
\patchcmd\@outputdblcol{% find
  \normalcolor\vrule
}{% and replace by
  \latexcolumnseprulecolor\vrule
}{% success
}{% failure
  \@latex@warning{Patching \string\@outputdblcol\space failed}%
}
\makeatother

\begin{document}
\lipsum[1-5]
\end{document}
Related Question