As for colour, that just depends on what type of weapon it is as they all look different, you can't get different varieties of the same type if thats what you ment, except for a few like longbows. Remember you can also dye certain parts of weapons.
Also, if you were talking about the colour of the items name, you can get:
white = common
blue = uncommon
purple = umm..very uncommon...
gold = rare