How to copy an object, and SLIGHTLY edit the copy's material w/o changing the first?

So I have an object, and I want to copy it 4 times in different colors. But I have specific materials on the object so I don’t want to recreate it each time just to change the color. But when I do change the color, it changes the original. How can I avoid this? I’m guessing I have to duplicate the material and change its name somehow?

By default, when you duplicate an object, the material isn’t copied, it simply gets an additional “user”: it’s shared between the original and a copy.
To make a full-blown copy, click the button with the number of users in the datablock name:

If you want duplication to always copy the material as well, you can set it up in User Preferences -> Editing section (look for “Duplicate Data”).

Thanks, solved!