Cleaning your gear

I have a large collection of underwear and am curious how everyone cleans their gear. Of course I never wash them in a washing machine/ dryer. I hand wash them in the shower in a container with a bit of Woolite Laundry Detergent. I then hang them up to air dry in the shower. Even using this simple and safe method, I find that neon and metallic colors fade. Has anyone found a better way to keep their underwear looking good?

Unless no staining, Just luke warn water. Mostly what I do.

All very similar - Dr Bronners Castile soap does the trick and its biodegradable! I do machine was on gentle every so often to get a proper deep clean…but never use the dryer!