Changing background color in a two columns page [duplicate]

I want to have this result: The first column in grey and the second color is white:

I am using \usepackage{multicol}.

your question isn't so vivid, but I prefer tikz and atbegshi.

\documentclass{article}

\usepackage{tikz}
\usepackage{atbegshi}
\usepackage{lipsum}
\usepackage{multicol}