I washed my brother's red shirt in bleach
Did you do that by mistake?
No, I did it on purpose and I ruined it.
I think it's very malicious of you to bleach your brother's red shirt as you may have ruined a shirt that he really liked. So that he may be able to forgive you, try to buy him a new red shirt just like the old one, and then you won't feel as guilty as well.
Whatever nerd! He doesn't even wear that shirt anymore.
If this is a shirt that was going to be thrown away, then there was probably no harm done. But I still don't think you should have deliberately ruined his clothing. I think you should apologize to him.