I separate by the kind of detergent and cycle a thing is run on.

Gym/sleep t-shirts, denim, towels all get a hot wash with oxi-clean and fabric softener because I love the smell come at me bro.

Elastics - things that are mostly elastic/spandex/polyester - socks, underwear, leggings, sports bras. They get a hot/cold wash with a pre soak and extra rinse. The detergent that washes cleanest and leaves no smell.

Daily wear/delicates - gentle cold wash with woolite with low tumble dry or hang dry. I only ever have like 4 of these with each wash. Generally the nice, more expensive stuff I wear in public that I want to last a long time.

I don’t care what color anything is.