Tink, I use quite a bit of oxygen when I use the Iris Gold (one of my all time favorite reduction colors). I give it a little shot of propane at the end, but I always go back in with a quick flash of a neutral flame before I pop it in the kiln. Remember also that there are lots of different Iris Golds. There is the Light Iris Gold, Medium Iris Gold, Dark Iris Gold, by Reichebach and Kugler then of course the Gaffer Iris Gold Lustre--all of them will give you completely different results. And yes as Alex said, the base color you use will play a big part as well in the final look.
Here are a couple beads with Iris Golds with silver foil, some over clear, and some reduced more than others to get the deep dark caramel color. I especially like it over Bullseye French Vanilla with a little bit of silver.