CRs:
The Taiwanese firm "Jagwire" makes top-notch brake cables & lined brake casing (housing) in a variety of colors. They also make matching STI & Ergo-style derailleur casing and cables too.
CR's Eric Meddaugh has nicely mentioned that Lickton's in Chicago (Lickbike) sells the Jagwire brake casing in 25 foot rolls, which is a great price if you need a large amount in a single color.
However, if you don't need that much, Branford Bike (now in Seattle, WA) sells individual bike casing sets in a variety of colors for a reasonable price. They call it the "Le Tour" brand:
The Jagwire brake housing measures about 4.8 mm in diameter, which might manage to fit thru the braze ons of older bikes. (Check your own bike, caveat emptor!)
In comparison, the later Campy housings which are teflon lined measure about 0.4 mm larger diameter; I get 5.2 mm OD. These casings definitely didn't fit braze ons sized for the older, non teflon lined stuff.
Hopefully your LBS can get Jagwire, too.
Andrew Gillis
brisk winds but fun riding in Long Beach, CA