Hi and thank you all for your input. The majority of my lights are white or off white though I do have a good handful of light prints (along the line of shirtings). The darks are more varied. The sashing, binding and back won't be from my stash so I'll have some control there and I'll try to keep those very simple. I do like somewhat of a controlled scrappy look and was thinking of doing it all blues, or earth tones or even buying one solid fabric for the lights or darks to keep things consistent. I opted out of the later because I really don't want to buy more fabric and in the end depending how much I have of each color I may opt to put it together in such a way that each large block of 16 squares is all similar colors, more or less. We'll see how it goes . . . .
Now I have to begin the daunting task of making all those HST's. And then pressing the seams. Once that's done it's all downhill.
My previous mud soup quilt actually turned out okay, BECAUSE, for the back instead of buying new fabric for backing I look my blues and made 5.5" squares, sewed those together and that was my back. It's still very scrappy but looks a lot better than the front. I'll post pics later.