Rit Dye is a common, all-purpose fabric dye which can be used to on many types of materials, including items made fully or partially of nylon. Other dyes, however, may offer better results.
All-purpose dye such as Rit is a type of hot water dye containing a mixture of different dyes. It contains both acid dye, used for dyeing animal fibers as well as artificial materials such as nylon, and direct dye, used for dyeing plant-based fibers such as cotton and linen.
All-purpose dye is at its best when used to dye fabrics made from mixed materials. If the fabric you wish to dye is only partially nylon and also contains plant-based fibers, using an all-purpose dye will offer the best results, as both types of dyes present in the mix find a use. If, however, the fabric you wish to dye is entirely nylon, you will obtain better results using an acid dye instead of a mixed one.
It is possible to dye nylon using food coloring or colorful drink mixes such as Kool-Aid. This is because food coloring belongs to the acid class of dyes; it attaches to animal fibers as well as nylon by forming ionic and hydrogen bonds. Dying clothes with food coloring can be a fun, safe project for kids to do.