Grouped bar plot with manually specified colors for each bar in the groups

My basic question is this: how can I manually specify the different colors that will be used to color my bars? In this specific instance (code below), I have 4 groups each with 4 bars. Each bar represents the magnitude of responsiveness of a neuron to a particular stimulus. Each of the 4 bars for each group is differently colored according to MATLAB's default settings. However, I would like to specifiy the colors manually in order to make these data consistent with colors I use elsewhere.

I generate the bar plot like so:

figure; h = bar(dFF_ROIs); if units == ['Z-score'] ylabel('{\bf Z-score (mean dF/F)}') end hold on for b = 1:numROI set(gca,'XTick',[1:numROI],'XTickLabel', ROIs2) end xlabel('{\bf ROI analyzed (area, stim location)}') title(['{\bf', mouse, ' ', num2str(unique(Reps)), '-day avg.}']) legend(x_axis_units,'location','Northeast')

There are 4 stimulus types, specified in a cell array called 'x_axis_units' which you can see appears in my legend function at the end. Additionally, I have specific an array of the color I want:

CS_colormat = [0 1 0; 1 0 0; 0 0 1; 0 0 0];

Ideally, I'd like to assign each of these 4 colors to each of the 4 bars in each group (in this case, 4 groups of 4 bars). In other words, the first bar would be green, the second red, the third blue, and the fourth black.

Is there a straightforward way to do this? Unfortunately there doesn't seem to be a simple 'color' input for teh bar function like there is for the plot function.

Thanks!