Okay, having lived around buff's for a good ten years or so, having been to open houses at MAFB and living there for a great many years, and having had the misfortune of being related to an -idiot-brother-in-law who worked on BUFF's for ten years, here's what I can tell you:
This MAY or MAY NOT be true, but is the result of several conversations with pilots, maintenance people, reading TO's and conversations with said Idiot-Brother-in-law.
The reason that the portkway stripes are different fromt the starboard walkway stripes is more a matter of internal bracing needed for the hydraulic actuators and mounts for cables. If that is untrue, then I apologize in advance, but I will qualifiy it by saying this:
"That's what everyone has told me so far!" :)
Hope this helps! If you have any more questions on BUFFs please send me an email at snipped-for-privacy@mnstate.gotohellspammers.edu (remove the gotohellspmmers bit) and I'll be willing to scan in any pics or info that I can give you, or at least point you in the right direction for more i\nfo if I can. :)