Here's directions for making a striped lumbar pillow with a bow inspired by one by Garnet Hill. I will say I am not a fan of painting fabric. I would definitely opt for purchasing striped fabric to save time. Just call me lazy or practical.
Also take a t shirt that covers the pillow with at least inches on all sides. cut strips and tie together. for scrunched edges and not shaggy look. turn pillow case inside out after the side is tied. tie the tight. no sew pillow!