Use a single tab field separator in keywords.txt

Each field of keywords.txt is separated by a single true tab. When you use multiple tabs it causes the field to be interpreted as empty. On Arduino IDE 1.6.5 and newer an empty KEYWORD_TOKENTYPE causes the default editor.function.style highlighting  to be used (as with KEYWORD2, KEYWORD3). On Arduino IDE 1.6.4 and older it causes the keyword to not be recognized for any special highlighting.

Reference:
https://github.com/arduino/Arduino/wiki/Arduino-IDE-1.5:-Library-specification#keywords

keywords.txt

@@ -22,11 +22,11 @@ get_register	KEYWORD2
 #######################################
 # Constants (LITERAL1)
 #######################################
-GATE		LITERAL1
-SYNC		LITERAL1
-RINGMOD		LITERAL1
-TEST		LITERAL1
+GATE	LITERAL1
+SYNC	LITERAL1
+RINGMOD	LITERAL1
+TEST	LITERAL1
 TRIANGLE	LITERAL1
 SAWTOOTH	LITERAL1
 RECTANGLE	LITERAL1
-NOISE		LITERAL1
+NOISE	LITERAL1