Wool dyes are used for changing color of wool. These dyes comprise a set of 16 dyes including:
Seven "primary" dyes - red, yellow, blue, green, white, black and brown
Seven "secondary" dyes
Two "tertiary" dyes
The possibility of dyeing wool indeed opens new possibilities for needle felted projects as well as other wool based crafts.
Dyes can be placed with wool on crafting table to dye a single block
Dyes can also be used on sheep to paint them and after shearing the wool dropped is of same painted color. After shearing, wool dropped is of painted color as well and this process helps in yielding more colored wool than from crafting procedure Here, one needs to note that there are naturally occurring gray, light gray, black, brown and pink sheep that have corresponding colored wool on them where you can only dye white wool via crafting and painting colored sheep is only way to dye non-white wool.