In the past I tried to change the color of the (Clarion) Progress control. What ever I set, it stayed green. So I left it as: "will look in to this later". In the Window 10 Newsgroup I read an article about that (about January 3/4 2018).
"I have FOUND IT!
Option in Global Properties, App Settings tab, Application Manifest.
"** Do not use Themed Controls "
With the option enabled, the progress bar color is now controllable.
I tested it and set the color: 'SelectedFill' to red: yes it's red now.
But I do not know what the effect could be on other controls.