The laundry will be light pink, the green color of the US bank note is actually an optical illusion deliberately put there as a counterfitting meassure, they use red dye but only the reverse side of the dye to make it appear green, it is similar to red/green color blindness.

Then when you launder the money, the dye gets jumbled and returns to it's red color, this is mostly noticable on the normal laundry since dollar bills.