I was wondering if the decks of Japanese carriers during WWII were wood. played a naval game back in '04, and the decks of the big Japanese carriers were yellowish-brown

The flight decks of most WWII carriers were made of hardwood (with some overlaid with light armor), and the same was true of large ships like battleships.

There are two main reasons for this: 1. hardwood is fireproof, waterproof, insect-resistant, and lightweight; 2. it is easy to repair if it is blown up in battle. The second point is the main reason, imagine, if it is armored steel made flight deck, once hit by a bomb, blowing through not to mention, but also deformed and bent, repair is a lot of trouble, but if it is a wooden deck, just need to be blown off the part of the replacement on the line.

And modern aircraft carriers, because the weight of the shipborne aircraft greatly increased. World War II period, the average shipborne aircraft but a few tons, now the shipborne aircraft are generally 10-20 tons, the wooden deck has not been able to withstand this weight, which is why it was changed to mounted armor steel, and, now the maintenance technology and equipment, than the World War II period there is a qualitative change in the improvement of the inconvenience of maintenance brought about by the steel deck, has dropped to an acceptable level.