Here is the Notepad++ defined language file.
Brief explanation.
Keyword List tab.
Green color - Most keywords
Blue color - autoit library.
Purple color - any word with prefix "k".  We make all of our keywords start with lower k so we can tell them apart.  ie kSetup, kLogin, kJumpUpAndDown
Orange color - keywords we created.  I just noticed I am missing my sikulit ones here.
Comment & Number.
Blue color - all the variations of comments.
Operators
Gold color - this is for variables
Also go have it setup to show tabs and spaces (view->show symbole->show white space and tab).  This is because we have our scripts tab delimited to make it easier to read.
The only initial pain was gathering all of the keywords from each library, pasting in excel and do some cleanup, then paste back into Notepad++.  Once you have this you can mix and match how you want library syntax formatted based on the 4 available sections.
This is a general idea of how we did it.  Add a new post if you have more questions.
Greg