The first one gives the Irish chain effect, the others don't in my opinion. Besides I like the color choices better in the first one as well.
I would use additional colors to increase the randomness if that is your intent. Otherwise keep your colors in the exact same positions in each square (not my favorite choice).
This is going to be really pretty in the aqua with the random additional colors!

I love number 1... then number 3

First one does it for me.