How do you dye them back to thier original color?

CELLULOSE FIBERS

Cellulose fibers are typically those made from plant matter and include cotton, linen, rayon, hemp, ramie, lyocell (Tencel), bamboo, and pineapple plant fiber.

Best fabric dyes for cellulose fibers:

• Fiber reactive dyes (best results)
• Direct dyes
• Vat dyes
• All purpose dyes
• Naphthol dyes

Procion MX dye is the most commonly used reactive dyes on the market and typically the best dye choice for cotton and other cellulose fibers. Jacquard’s product is well known among seasoned fabric and textile dyers to be among the best and easiest to find. When it comes to dyeing cellulose, Procion MX is the go-to choice for durable colorfast dyes that are vibrant in color.

I have had good not great results re-dyeing. Remember not to mix cooking pots and dyeing pots.