First post on Flower Temari Challenge gives info on making and marking the ball.
Begin by using a thin metallic thread to divide the pentagon into twenty sections. Place the stitches for the inside points very close to the center intersection. For the outside points, place stitches for the first row 1.5cm from the outside border (the triwing stitching).
Using Caron Watercolors # 057 Buttercup, stitch a layered kiku herringbone design, adding enough rows so you almost reach the triwing stitching. Leave enough room for two more rows. Stitch these with #206 Guacamole. (Don't you just love the names of the thread colors?!)
Fill the center with French knots using #057 Buttercup. Use one strand of thread in the needle and wrap three times for each knot.
Add a bit of sparkling green metallic between the kiku sections in the centers.