As for the "red" colour:

I recall that the Japaneseicon treated the timber with Potassium Permanganate as a mould / rot inhibitor. Creosote works but it has a rather distinctive smell and is a nasty skin irritant, not "features" to be desired on a combat rifle.

On the other hand, Australianicon coachwood, as found on Lee Enfield and L1A1 stocks, often exhibits a faint whiff of Creosote, especially when "heated up".