ST editor syntax colors

Syntax coloring makes it easier to read code elements. You can set the color and the font style of each syntax item under Extras > Options > Program options > Fonts and colors.

Color settings for syntax coloring:

Element	Modifies color settings of
Text	Text elements
Global variable	Variables which are declared in the global variable list
Local variable	Variables which are declared in the header of the POU
System variable	System variables, e.g. `sys_bPulse1s, sys_iRingCounter_2ms5` Special flags and addresses, e.g. R901C, DT90019
Global function block instance variable	Function block instance variables which are declared in the global variable list
Local function block instance variable	Function block instance variables which are declared in the header of the POU
Function	Functions, e.g. ABS, COS
Parameter placeholder	Placeholder for function and function block parameters. The placeholders are marked with the ? character, e.g. `SEL(G := ?BOOL?, IN0 := ?ANY?, IN1 := ?ANY?)`
Operator	Operators, e.g. `( ) , :=<>`
Keyword	Keywords, e.g. `FOR`, `IF`, `THEN`
Number, constant variable	Numbers, e.g. `123`, `16#123`, `TOD#15:36:55` PLC type constants, e.g. `SYS_FP7` System constants, e.g. `SYS_PI` Variables of class `VAR_CONSTANT`, `VAR_GLOBAL_CONSTANT`
String, constant string variable	String literals, e.g. `'abc'`
Comment(* abc *)	Multi-line comments enclosed by round bracket and asterisk
Comment/* abc */	Multi-line comments enclosed by slash and asterisk
Comment//abc	Single-line comments introduced by two slashes
Address	Addresses, e.g. R0, DT0, %IX0.0.0
Monitoring	Online monitoring values
Forced variable	Forced Boolean variables and bit addresses