I would suggest using FRAPS instead of the built in TS frame rate viewer. FRAPS is more accurate, the built in frames counter never goes below 14FPS.
http://www.fraps.com/download.php All you need is the free version (unless you want to make videos) You can change font color easily, change the corner the frames counter is in, and take screen shots.
I don't like messing with files in TS, most times an update or file verify resets it all back to default anyways. Maybe someone else knows what file you can change. Oh, and,

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