Here's a simple tutorial on dyeing fibers. All of these were dyed in less than 30 minutes using Ribbonsmyth non-toxic dyes. Once dyed, they were heat-set in the microwave.
I mixed silk dyes and rayon dyes together.
In this photo: double-sided silk satin, brown and mauve nylon single-faced velvet, a gray rayon motif, 2mm silk cord, glitter velvet, white silk ribbon and silk carrier rods. Whatever you have on-hand, dye it!
Nylon fibers will dye only in pastel shades.