this is funny cause i just learned this in biology last week...

the colors we see are colors the object is reflecting back ..say for example a pair of jeans are blue because they do not absorb blue as easily as the do the rest of the roygbiv group..its also interesting how they make jeans look rugged and stuff they used to stone wash them or watever using stones and water in a method to age the fabric and now they use a chemical compound called cellulase which is an enzyme that breaks down the cotton because after all cotton is a plant..