Question about Proto yellow wrenches
 

I have a friend who has quite a few sets of these Proto wrenches. I am curious as to why they are painted yellow. I think they are 10 to 15 years old. Never been used. 

http://img268.imageshack.us/img268/6292/sam0377jk.jpg

WAG alert: Perhaps these were to be used around aircraft, and the color made it easier to keep from leaving one behind. I can find nothing to support that, nor anything else about these tools.

SUPERCOMBO® Combination Wrenches: High Visibility | Pro Tool Warehouse

High Viz wrenches aren't too uncommon.

You might have something there. My friend's son was a sheet-metal worker on aircraft during Vietnam. I ll betcha that's where they came from.

Yes, the "spanner in the works" must be avoided, especially in aircraft!:-X03

Just as an aside, Proto makes pretty good quality tools.

Proto is one of the professional divisions of Stanley Tools now.
I have my grandfather's Proto wrenches.

some painted them

The factory painted them.