Polyad colors by jpwesterhof · Pull Request #126 · bgrins/TinyColor

This sounds like a cool idea. These need to pass arguments to _applyCombination like the other public methods. So, just make the private triad and tetrad functions call polyad with 3 or 4 as n.

triad: function() {
    return this._applyCombination(triad, arguments);
},
tetrad: function() {
    return this._applyCombination(tetrad, arguments);
},
polyad: function() {
    return this._applyCombination(polyad, arguments);
}

...

function triad(color) {
    return polyad(color, 3);
}

function tetrad(color) {
    return polyad(color, 4);
}