Peachy, I think your gray is fine. Take a look at Krista's quilt above. Her constant wasn't highly contrasting and it looks great. Looks to me like Krista also didn't do scrappy. The design came out great and so will yours. All our quilts will look a little different due to fabric and color choices but I haven't seen one I don't like, even in colors that I never would have thought of putting together.