How do I prevent my laundry from bleeding onto itself?

So I have a pair of St. Louis Cardinal swim trunks that are red and white. Like I do with all new clothes, I washed them before wearing them. I washed them by themselves, and used cold water like the instructions said. Well, the red somehow bles onto the white anyway. Not a big deal, because I called the... show more So I have a pair of St. Louis Cardinal swim trunks that are red and white. Like I do with all new clothes, I washed them before wearing them. I washed them by themselves, and used cold water like the instructions said. Well, the red somehow bles onto the white anyway. Not a big deal, because I called the manufacturer and they’re sending me a new pair. Now here is where my question comes in.

So I know if I wash this new pair immidietly like I did before, they will bleed again. How do I stop this in advance?? I will obviosuly have to wash them at some point. Is there a way to set in the red dye so that it won’t bleed?? If it helps, I will be wearing them in the ocean, so would it help to let them come in contact with salt water first?
1 answer 1