happylab, I routinely check on Etsy, searching, 'low volume fabric bundle' for lighter neutrals. Of course, this will usually involve separate shipping charges, which can add up.
L'il Red Hen quilt shop makes it easy to search for neutrals, as they have a 'by color' option and a neutral section. Last time I checked they would sell 1/4 yd. (but not a fat quarter).