I'm not sure if I understand your question correctly, but as far as I remember you can change bar colors in Excel. Check this out: http://office.microsoft.com/en-us/excel-help/vary-the-colors-of-same-series-data-markers-in-a-chart-HP010007429.aspx

Is this what you need?

Yes, that is the case. By the way you have to change many bar colors or create a macro for this. But is there another graph different from bar plot?

Would you elaborate a little more on what you'd like to do, and what those groups are?

This is the case: you have a class (males and females). You want to show in a plot how are variable the grades in X subject and in the same time the ranking. I wish to obtain the effect of a bar plot and a boxplot together.

This is a stripplot, done in Stata, with superimposed boxplots. The stripplot command, written by Nick Cox, will also superimpose means and confidence intervals (these can be calculated as normal, binomial or poisson). You can install it in Stata by typing

. ssc install stripplot

I post one possible solution for the problem. This is an application to Rule of Law ranking 2013.

In some cases you have some groups/clusters and you need a graph to highlight the differences in a ranking between the groups. It is very similar to the histogram with cluster. Also in this case you may opt for a VBA macro to facilitate the graph realization.