static S substanceLAF_defaultSkin = "Creme";

static void substanceLAF() {
  substanceLAF(null);
}

static void substanceLAF(S skinName) {
  pcall {
    enableSubstance_impl(or2(skinName, substanceLAF_defaultSkin));
  }
}

Now also makes frames LAF-decorated (nicer, and makes title bar modifiable!)

Skins:

http://insubstantial.github.io/insubstantial/substance/docs/skins/toneddown.html
http://insubstantial.github.io/insubstantial/substance/docs/skins/dark.html
http://insubstantial.github.io/insubstantial/substance/learn.html