Change layer color in layer palette

There's no Domestic Oriented Model method for this, so you are limited to write own Action Manager function that after all would be source for future DOM way to get the same. You can only write it more readable (whatever you consider for that):

function color(color) {
     function sTT(v) {return stringIDToTypeID(v)}
     (ref1 = new ActionReference()).putEnumerated
     (sTT('layer'), sTT('ordinal'), sTT('targetEnum'));
     (dsc1 = new ActionDescriptor()).putReference(sTT('null'), ref1);
     (dsc2 = new ActionDescriptor()).putEnumerated(c = sTT('color'), c, sTT(color))
     dsc1.putObject(sTT('to'), sTT('layer'), dsc2), executeAction(sTT('set'), dsc1)
}
color({1:'none', 2:'red', 3:'orange', 4:'yellowColor', 5:'green', 6:'blue', 7:'violet', 8:'gray'}[7])