Changing chart's stripe color faster ?

Hello,

I have this type of chart (Fig. A):

(Fig. A)

On the axis, A, B, C etc. represent a department and the chart shows a value for a topic. I follow the evolution of this value, monthly, for each department.

The thing is, I always have to manually change the color of each stripe so all the stripes for A is blue, B is yellow etc. If I use the "modify color" or by default, my chart will look like this and which I don't want to (Fig.B) :

(Fig. B)

Is there a way to modify colors to get something like fig.A without doing it manually ?

Thanks for any help !