How was this teal line added underneath this text box and how can I change its color?
here is what it looks like when I zoom all the way in at the bottom of the text box

How was this teal line added underneath this text box and how can I change its color?
here is what it looks like when I zoom all the way in at the bottom of the text box

I’d say that’s a Paragraph Rule.
See Paragraph Rules on the Paragraph panel menu.
thank you! this is what it was.