Generally speaking a refractor gives you that rainbow effect when the light hits it, as it is refracting the light. If you have one in hand, you can definitely tell the difference between a standard chrome card and a refractor. Also, refractors tend to scan much better than chrome. An Xfractor usually has some kind of grid design where it looks like the surface is broken up into a lot of little refractor squares. Superfractors typically add some sort of texture to the surface, often adding a sort of circular effect to the refractor squares.
Colors are just colors. They take replace the basic color scheme of the border design with red, blue green, black or whatever.
Here's a YouTube video with someone showing off some Bowman refractors (good ones at 1:36 and 1:56) and a Superfractor (at 3:45).
https://www.youtube.com/watch?v=EtBj0FeWkTA
Here is a regular colored refractor:
http://www.tradingcarddb.com/ViewCard.cfm/sid/19111/cid/2403872/
And here is the same colored xfractor:
http://www.tradingcarddb.com/ViewCard.cfm/sid/19119/cid/2405035/