Is this quilt from you or did the MOB commission it? It's a key point that hasn't been mentioned yet...or that I missed?
If it's from you, you must know the bride pretty well in order to make such an elaborate wedding gift. And if you know her well (better by far if you know them both well), you may have a little leeway on any added colors. Still, it's very risky to add spice to a 'pastel lover's' wedding quilt.
If it's from the mother, there's no question that you should not be adding colors to those selected.