Let me try a different approach.
I currently use a clusterd column chart that is created automatically
with code.
Presently, I need to select each column manually to format them
according to a convention that we like at work.
Each column that represents a subset of a given group is colored to
represent the group of which it is a subset.

Each column that is of a different group gets a different color.

I think I can automate this process if I can tell the code to look at
column 1, for example. Then column 2, and so forth through the entire
set of columns. If I can do that, I can provide an IF then statement
in the colorindex definition that will color it according to the proper
grouping.

Is there any way to either define a numbering sequence to the columns,
or is there already one that I can tap into?

TIA