Good Morning. Since the dark jeans look is in, this tip might help keep your jeans looking new longer.
Fading: Turn dark clothes inside out and wash in the coolest water possible; dry on lowest heat. For all-black clothes, throw in a box of black Rit® dye every 8-10 washes or so to keep black clothes black.
I don't know about the Rid dye...I'd be worried about the next load of clothes getting residual dye on them. That part is kind of "iffy" to me.
Have a good day!
Welcome to any new readers & hugs to all my friends!