You are limited what you can do controlling graphs in Dynamic without resorting to injecting script into the rendered page using the rules tab in report design. I don’t know how you could use @PAR#@ to control styling, but you can with user profile @ALIAS#, including on ‘rule script’ tab. This BLOG gives examples of that and also using script to impact formatting: Deliver Better BI With Dynamic AI Styling

You can suppress totals, and also assign colors, using this, admittedly kludgy, method as described in these release notes doc from 2014:
Build 6.4.46
You can set specific colorcodes on the charts using @chartcolor:colorcode in the grouping text. The @chartcolor:colorcode will not show on the list.
Use @chartcolor:hide to hide a total from being used in a chart.

This is saying that if you caption the column name to something like: Total Dollars@chartcolor:hide – then the report grid will display “Total Dollars” but the chart will not plot that total. Or instead of hiding a total, you can force the chart element for that total a specific color. You could also control colors in script.

Since the interactive charts (Highcharts) are themselves written in javascript, you could do a lot of customization with .js programming in the rule script tab. The referenced BLOG just scratches the surface for that.