changing the color of visted hyperlinks in a text block

I need a hyperlink to show it's been visited. In my project hyperlinks reveal more details of the story, but I see that learners have no idea of where they have been, as there is no visited hyperlink color.

I've hunted around and can't find any settings for this.  I puzzled as I thought this was the web standard.

It would be very helpful to add this simple interactive component. I'm dealing with complex scenarios and the hyperlink displays a layer of more information, as needed. And it is unobtrusive.

I could overlay a hotspot, but as the text is edited later, the hotspots will need realigning; plus it still wouldn't show a state change.  Using a button for the text would require some super aligning to get the button text to match the text underneath, not to mention any future editing problems.

Am I missing something? Is there a way for learners to click on part of a text and it shows they have done this?

Thanks.