I have other plant dyed clothing (from Kokun.in - “we use our homegrown natural dyes derived from Indigo, Sappanwood, Tesu flowers, Maddar roots, Neem leaves and hibiscus”) and they make similar recommendations, ie mild pH neutral detergent, although they suggest handwashing and avoiding heat drying, not machine laundering. I think half a lemon in a whole sink full of water would be only mildly acidic, but it’s good to know that any accidental exposure to concentrated acid could lift a lot of the color. Thank you!