center image when's bigger than textwidth

center image when's bigger than textwidth

I have an image that is larger than the line width and I want to center it
and I also want to have a colored frame around. I can get this two things
done one at the time, but don't know how to achieve both!
for the colored square I use this:
\newcommand{\mybox}[2]{{\color{#1}\fbox{\normalcolor#2}}} %in the preamble
\mybox{grigio}{\includegraphics[scale=0.43]{life.jpg}} %in the document
I manage to center the image with this code:
\begin{figure}
\centering
\makebox[\columnwidth]{\includegraphics[...]{...}}
\end{figure}
Note that I don't want the image's width to be = to the text width. I want
it bigger, but still centered. Thanks ;)