"He who marches out of step hears another drum." ~ Ken Kesey
It's the garment, not anything you are doing. Red's are hit and miss with discharge.
yup, eb is right. we've had the same issues. Some stay nice and white, some turn a bit pinkish
Have you tried running one through the dryer first, reduces the moisture level in the shirt. If you have the ability to weigh the shirt before sending it through you'd know that could be a contributing factor...