Click Desktop Settings in the Preferences menu. It lets you select the colors and fonts for the Robot screen display.
Option Color (selects the color for displaying an element) is active when there is text defining an element in the Element dialog. It is inactive when:
Option Font (selects an appropriate font) is active when there is text defining a font in the Element dialog. It is inactive when:
Option Add is active when you enter new text in the Scheme dialog and define your own color and font scheme.
Fields Range (grouped elements for which colors can be changed) and Element (selects elements for which colors and fonts can be changed) are inactive when the Scheme dialog is in the text edit mode: