There's some big fans of PVC who read this blog, and the common choice of coloring is through a rattle and shake spray can. We all know it doesn't hold up very well over time. Many plain white extension cords are also covered with PVC, and Make: has created this short video tutorial on how to color dye PVC based on the article found here: https://makeprojects.com/Project/Cable-Dyeing/750/1

Now, go out and get colorful with your rigs, or maybe just go with the cliche all black..