Here is my immediate suggestion: Show only one palette at a time. By putting incompatible patterns so close, you get a matrix of colors that with high probability do not harmonize well.

I am assuming you have a slightly different algorithm for these three, since the middle one doesn't seem to match the root color's brightness, and they seem to match saturation differently too. Make a choice between these before you generate, and if you want to eliminate this choice, I would go with the one that tries to match brightness/saturation as much as possible.

This caught my eye because I developed my own algorithm for this a few years ago and applied it to syntax highlighting[1].

[1] http://sweyla.com/themes/