How to specify a specific color to each column in Splunk bar chart?

Question

I have bar chart with next search query:

<chart>
  <search>
    <query>sourcetype=st AND logger=lg AND (message="A" OR message="B" OR message="C")
          | stats count by message
    </query>
    <earliest>-48h</earliest>
    <latest>now</latest>
  </search>
  <option name="
         •••
            </option>
</chart>

How to specify a specific color to each column with next logic:

if (message="A")
  then color = 0xFF0000
else if (message="B")
  then color = 0x00FF00
else if (message="C")
  then color = 0x0000FF

Thanks!