The best place to start is with the manufacturers of the equipment. They will always have a care/maint. section.
Pro: tools looks look great
Paint used in moderation can be used to mark tools and helps to get the tool back to the correct company. NOTE the word moderation.
LIGHT coat of oil will help in keeping bare metal rust free
cons: paint covers defects that may increase safety issues and possible injuries to firefighters
Never paint wood handles, paint covers cracks and increases the probability of injury to firefighters. Boiled Linseed oil has been used by departments in the past, be sure it does not get applied to areas you use as a grip as it tends to get slippery when wet.
Paint adds resistance to cutting tools and causes the tool to stick in wood when being used. Sticking adds to increasing the probability of injuries to firefighters.
So the question becomes as the old Starkest tuna advertisement, tools that look great, or safety to the firefighter.
On a side note, We are working on IFSTA VI and talked about this less than an hour ago. This was the recommendation we agreed on concerning painting tools.
Axe blades should NOT be painted. Use a wire cup in a right angle grinder and get all the paint and all the rust off, While some have had luck with oiling axe heads to me it never lasted long enough, particularly in the winter, before rust appeared again. We use a product by CRC called SP400. It is kind of like a spray on wax that coats and protects the blade. It had caused absolutely no problems in using the axes. It is a little pricey. I have learned that the best way to apply it to any metal surface is 2 LIGHT coats, let me say that again 2 LIGHT coats. Otherwise it takes forever to dry.
Whatever you do, do not use a grinder to sharpen your axes. You can use a file to lightly clean the edges. A bench grinder will mess up the temper of the steel and destroy the blades.