Possible Duplicate:
Parametrize shading in table through TikZ
Is there any package that provide conditional coloring in LaTeX ?
I would like to reproduce what Excel does with its conditional formatting feature, e.g. :

In my example I would like to specify two colors (here red and blue) and format a tabularenvironment such that cells background-color varies linearly between the two specified colors depending on the max/min value found in the tabular.