Thanks to everyone who helped me decide what to do with my snowflake Zendala. I decided to go with Cat’s advice and use blue. I used about 10 different colors of Prismacolors in shades of blue, white, and silver and used them as if I was shading it. I really enjoyed this process and think I will have to explore it more. Here it is in blue.
And, since I accidentally had my scanner set to black and white mode for my book; here it is in black and white. I think I achieved my goal of “shading” with blue. Except for the center, it looks just like it would have if I’d done it with pencil.
I’d love to hear which you prefer.