Well usually all the grains you add only darken the beer. How light the beer is starts with the lightest malt you use, or extract in your case, although you can use something like Pilsner malt or extract which is a lighter base color. Or flaked wheat can really lighten your beer, but that requires mashing with some 2-row. Some crystal malts can make your beer a more golden color, like small amounts of c20. I'd say it's a richer yellow color, but pretty much every specialty grain will just darken your beer to a degree.