The term 'Wash' is probably borrowed from the painting technique. When painting with a wash, it could be seen as freshening whatever is being painted. Cloud washing refers to freshening a product by adding ``Cloud`` to it in some creative way

The Dark Rinse is a fabric that's dipped in darker dye after the jeans are actually sewn together, allowing for the dye to saturate all the seams for a soft feel and deep color. The Dark Wash is dark colored denim that's washed during production, which gives it a soft touch and adds unique texture.

Denim is a sturdy cotton warp-faced textile in which the weft passes under two or more warp threads. This twill weaving produces a diagonal ribbing that distinguishes it from cotton duck. ... The indigo dyeing process, in which the core of the warp threads remains white, creates denim's signature fading characteristics.

Enzyme wash is a process that gives denim a softer and worn-in look by breaking down the cellulose molecules naturally found in indigo dyes. ... Enzyme washing is a popular form of washing denim because unlike stonewashing, enzyme washingis more cost effective and will not stain or leave any residues.

Overdyeing is a process where the fabric is eitherdyed for too long or dyed a second time. It is most often used on denim to add an overtone of color to the indigo.