Very likely you could write down your Vehicle Identification Number and take that to an auto parts store or a dealer for the type of car you have. They can read the code to give you the exact color name. And as moe fugger said, the info could also be on a sticker in your car, probably inside...
Sure, you could use any of those materials, with certain conditions.
Wood is strong and rigid and if rigid enough, will protect the contents from heavier items or from bumps and such. Plastic can behave similarly, but many plastic containers are quite flexible. Metal can be very durable, but...