DEC,
I use Earls "Flame Guard" hose covering on the fuel lines in the engine compartment. Helps to plan ahead. Once the swivel fittings are installed you have to slit the fire sleeving and bind it up to get the sleeving on the line...
The smallest size for the hose covering I think is 3/8", pretty big for a brake line. Could do it, no one would see it, just would need to work around the small nylon clips/brackets that currently hold the tubing in place.
EARLS' also has a TAPE. Your brake lines are new, clean. The adhesive should stick well. Could wrap the brake lines with it in hot spots. Holley distributes Earls products.
Holley Performance Products Flame Guard Tape*731001ERL
Any inert tubing like the silicone Bob mentioned would probably be pretty effective.
Pete