Rusty bleach spots on black Serenity pants

Rusty bleach spots on black Serenity pants

Serenity pants are stretchy yoga/exercise pants. Mine are black. I accidentally washed them with a white top that had a stain I’d soaked with bleach. The bleach left some rust colored spots on my black Padagonia Serenity pants. Is there a dye for this kind of material I can use?