"white with green streaks" == sounds like the effects of a virus spread by plant pests like aphids or similar. It happens. Odds are once they have it, they may always have it.

If the effects aren't too severe, I'd just let them go. Some plant viruses that don't damage the plant too much actually cause desirable effects. For example, a lot of the variegation in things like Rembrandt tulips and certain camellias is viral in origin.