Hi Kim,
Try the Article Indicator extension. It gives a vertical progress indicator and the option to jump to any article in the course. Here’s a screenshot of a course with it turned on. It’s not as subtle as the header progress, but it does show the article name on hover over and click to jump.
The Article Indicator uses Theming > Default colours > UI Secondary Background for the circles and label colour, and UI Primary Text for the label text colour.
Whilst it is possible to change these colours for a Page Indicator (Theming > Extensions > Page Indicator, I cannot find anywhere where you can independently change the Article indicator colours.