grafana dynamic variable use

Question

suppose i want to change the color of the panel text based on a logic for example if active users are 3 and open issue is 6 then since we 2 issue per person color should be yellow and if open issue becomes 9 then then based on active user color should be red yellow=active user2 red= active user3 how can i implement it using variables and i am using prompetheus as data source
and metrice for active user is active_users{users="activeusers"} Open issue metice redmine_project_open_issues_total_count{projectname="Redmine Dashboard"}