I tried to implement this myself, but I couldn’t. The reason is that richtext cannot be a textbox, so I decided to put a transparent textbox on top of the richtextlabel.
But since you can’t see the cursor, it’s almost impossible to work with.
I think I vaguely remember having a similar experience at some point. I tried implementing my own cursor at first, but then I found a simpler solution.
What I did was put the TextBox ontop of the TextLabel and set the TextBox’s text transparency to 0.1
This way the color is dominant but the cursor is still visible