Printing in color when set to black and white

When looking at a PDF, it will be blank of color but when printed there will be highlighted sections. Under Preferences>Accessibility, the document color options are set to white background and black text. Also under Preferences>Color Management, greyscale is set to black and white. Issue went away after first change to Accessibility but it has now come back a few weeks later. In print preview, it does not show any color but once printed, it looks like a section of the text was highlighted.