My daughter was told to use Windex on the white or light part. She says she sprayed the Windex on the sleeves and washed and it came out perfect.
It really does work for the vinegar (1Cup per Load of new clothes, or less amount if doing 1 or 2 garments in a bowl) to set the color. My daughter just told me that she did as I suggested to soak the kids’ new clothes in the vinegar and then she washed them with regular clothes and there was no fading or dyeing other items.
I wish you well and God Bless.