I'll have to disgree with two things.

First, sirens:
I don't know what euro sirens you've heard, but our are two-tone air horns, putting out 144 dB at 5 meters. Enough to cause hearing damage within seconds even on someone wearing plugs. Which is why we have a little toggle switch for the 100dB mode, which we only really use in residential areas at night.

The other one is about helmets:
I prefer slime lime (glow-in-the-dark optional) to black, at least when issued. The color of a man's helmet darkens in direct proportion to the time he was on the force, with rookies almost too blinding to look at, and old hands black/stainless steel from the soot and the scratches. REAL firemen's helmets _should_ be black :P

As for the helmets: With nearly all (>95%) of all structures we go offensive on (so no barns, shend etc.), the cielings are rebarred concrete. You don't get water leakage or significant debris before the building actually collapses, so protection from that is not _that_ important over here.