I figured it out. Right click on a text column and select "Customize
Fields...". Towards the bottom, select the "Graphical Indicators" button.
Apply conditional formatting as needed.
In my specific case, stop light colors are being used as indicators for key
milestones. We associated an "R" entry (or "r") in the text field with the
red circle icon, a "G" entry (or "g") for the green circle icon, etc.