1. Use a pencil to mark a diagonal line on wrong side of each gray print 3-7⁄8" square.
2. Place a marked gray print square atop a coral weave print 3-7⁄8" square. Sew together with two seams, stitching 1⁄4" on each side of drawn line (Diagram 1). Cut apart on drawn line to make two triangle units. Press each triangle unit open, pressing seam away from gray print triangle, to make two triangle-squares. Each triangle-square should be 3-1⁄2" square including seam allowances.
3. Repeat Step 2 to make 20 coral weave triangle-squares total. Using purple weave print 3-7⁄8" squares instead of coral weave print squares, repeat Step 2 to make 16 purple weave triangle-squares.
4. Using purple, coral, or navy print 3-7⁄8" squares instead of coral weave print squares, repeat Step 2 to make eight triangle-squares in each fabric.
5. Referring to Diagram 2, lay out four matching coral or purple weave triangle-squares; eight matching purple, coral, or navy print triangle-squares; and four gray print 3-1⁄2" squares in four horizontal rows. Sew together pieces in each row. Press seams in directions indicated by arrows in diagram. Join rows to make a block; press seams in one direction. The block should be 12-1⁄2" square including seam allowances.
6. Repeat Step 5 to make nine blocks total.