sewingpup, the color of the cross arms has to be very strong and bright in order to show as intended, especially if the indigo has been used in clues 1 and 3 (the big HSTs). I've noticed some Quiltville quilts that used lighter colors for the indigo in those clues, and the cross arms stand out very clearly in those quilts. There was also one quilt that used a darker neutral for clue 4 (in A block), which made all of block A less prominent, and the cross arms stood out beautifully there. So I think it is a matter of strength and brightness of color for the cross arms, plus not setting up a competition between the cross arms and other elements of the quilt.