Assigned data series color changes automatically

[gouthamr5]

Hi,

I have a bar chart with 9 labels and i want to assign colors for each label. But every time i do that, it changes to the default colors assigned by excel in that particular order. I tried creating a custom theme but you can choose to only upto 6 colors. I clicked on the format series tab and selected solid fill but it changes to automatic once i change the sheet.
Please help me out with this one.

Thanks in advance,
Goutham