I think a subtler color sashing will keep it more vintage scrappy style than if you use black. Red maybe if your needing bright or blue would pull it all together. but not black.. lol kick me I don't care love you girl and you know it. on the center well yellow is flower like.. reds with orangish hints might be good to. I first thought blue myself but its cause I don't like yellow terrifically. I am thinking for a scrappy quilt this is going to be beautiful. I see hours and hours of work. Darn your a patient woman!
if we have fast groups I will join again. I hate the slow speed. And I love making blocks. Doing all the swaps is nuts and I agree expensive in the end. I did fifty once and doing them was ok it was too expensive for my limited budget unfortunately. So two groups maybe 30 or 35 is well topping it for me too.