I came up with the idea of using EL wire strips to go down the sleeves. Whit EL wire spirals. With RGB NeoPixels being used for other color effects on the shirt and pants.
Too bad the 3 volt, 2xAA battery, power for them don’t have intermittent power usage. I could probably make a program so an arduino could run the power for an EL strip, panel, or wire in a semi-random pattern. I don’t know enough to feel comfortable in doing this.
and I realized I had about 20 of the Mini-M&M bottles. So those might work for costumes. I haven’t checked to see if the printing can come off of them or not. They are in a box somewhere, and I haven’t located them yet.