Hi Jesse,
I actually got them from Grnedel here in the forum. I think he just took the png files into photoshop or something and re-colored them. If you want "them" I could dig them up for you, or you could just hue adjust your own Icons however you like.

MoI's UI is fully customizable. Either by structure with html files, or by the images that are what you are seeing there with the buttons and such.

Before the beta's started rolling out regularly, There were some guy's working on "Custom UI" skins (User=ASH) that you could apply to MoI that were very cool. I think when the next release rolls out, you may see a couple of these come out again...