Jacquard iDye for Natural Fabrics .49 Oz - True Red

I have a powder blue sham I want to dye a blue gray...how do I do that?

I have white 100% cotton chair slipcovers and want a dark gray would this work on its own or should I combine with black? Each slip covers weighs 4#s

I would like to dye some cotton, acrylic, nylon blend white socks grey. Would it work to use both the natural fiber and polyester dyes together?

I forgot to add salt to the dye solution, will it fade faster? . Thanks Irene