Thanks @cw-ch-scott,
I did note the ibcs-class attribute before posting my question, but it is unpopulated and I have seen the color attribute used more here, hence I posted my question about the color attribute instead.
Looking in }ElementAttributes_T Year-Month.rux I see the rule you were referring to. However, the Cubewise consultant(s) before me have commented the rules out for some reason. I am not sure why they did that exactly. I assume they must have had a reason why they want it turned off.
Regardless, writing the TM1 rule behind the attribute is the easy bit. I can either uncomment the existing rule or use my own.
The bit that I struggle with is how to utilise the values in either the color attribute or the ibcs-class attributes to impact the colours in the chart columns. As mentioned, the chart has no issue responding to values in the color attribute on the FIN Version dimension. However, it completely ignores anything I set in the color or now ibcs-class attributes on T-Year Month dimension.
Any tips on how to get the chart to respond to those attributes?
EDIT: I found this topic after posting my reply, which seems to indicate that ibcs-class only does headers anyway, and that the color attribute is what I should indeed be focusing on. Not sure if this is still the case, but posting here for reference:
*EDIT 2: Also, rereading that linked topic above… they mention that the color attribute is only referenced for dimensions on rows? Is that correct? As I showed in the OP, I have T Year-Month dimension on columns (where it needs to be). Could that be why Apliqo is ignoring values I place in the color attribute? If so… is there any possible work-around for this?