Different colored treasure goblins?

Check out this post on Treasure Creatures.

Of note is the following graph that shows some interesting trends for the different goblin types.

It looks like the loot distribution depends on the name, not the color. Take this data with a grain of salt though, the sample size was fairly low.

There is a rumor that it correlates to what kind of loot they will drop:

• Blue = magic item(s)
• Yellow = rare item(s)
• Green = set item(s)
• Gold = Legendary item(s)

This is a very tempting thought, but it has been tested to be untrue. Here is a thread where some of the testing is done, that disproves blue = magic only, gold = rare, etc.

I cannot find any other information on how their colors or names are chosen, but here is some more information on how they work in general: How do the Treasure Goblins work?