There was a bright green meteor streaking through the western sky over Seattle a couple hours ago (midnight-thirty-ish local time). Check out West Seattle Blog’s continuing coverage  to hear some first-hand accounts.
This was a bolide meteor (an exploding meteor/shooting star). It was part of the Quadrantid Meteor Shower. Read my article about why we see meteors  below if you’re interested in some of the science behind that.
Also, why colors? The same reason different fuels burn with different colored flames: it depends on the chemicals in the fuel. Green is commonly produced by copper when conducting flame/fireworks color experiments here on Earth–doesn’t mean the fireball had any copper in it, that’s just a related piece of information. It is also true that our eyes are very bad at determining colors at night–so the green could just be an optical illusion and not related to the composition of the meteor.
~ A l i c e !