Where are OF standard icons located
 

I have some scripts/perspectives that I'd like to assign icons to. I like the OF standard icons, but would like to modify/tweak them a little for my scripts and perspectives.

Are they located in a file that I can access? If so...where is it located?

They're stored inside the application package. You'll want to open it up, navigate to
Contents/Resources/
and then copy the PerspectiveImages folder out to your desktop. Modify the copies and use them; the folder inside the app package will be replaced when you update OmniFocus in the future, so you'll lose any changes you make inside the app itself.

(I'm deliberately being a bit vague here, because I don't want to encourage folks who don't know what they're doing to mess around with files inside the application.)

Thanks Brian...I'll try not to muck around with the app too much!