S T R U C T O R I Z E R - User Guide
Settings > Highlight variables?

Generally, all text in the diagram elements is written in standard font (black), but you may enable the option "Highlight variables?" in the menu "Diagram". This does not only highlight variable names, but also operator symbols, string and character literals, and certain keywords (also see page Syntax highlighting in the Features section and page Parser Preferences):

Diagram menu with highlight option selected

Alternatively, you may press <F4> to toggle the highlighting mode.

Here is an example for the effect:

 

standard diagram versus highlighted diagram

You will find plenty of examples throughout this user guide and, of course, in practical use - it's quite straightforward.

Remark: Before version 3.29-06, highlighting was the major cause of drawing contention, particularly in Arranger. Since version 3.29-09, these performance problems have been eliminated. Only the first drawing of a large amount of diagrams impirted by code or loaded from an arrangement file may take a few seconds, therafter the time difference to drawing without highlighting is hardly perceptible anymore.