I am a bit obsessed with this dress from M&S, but the amount of time it would stay white on me would be minimal ...
https://www.marksandspencer.com/v-neck-pleat-detail-midaxi-waisted-dress/p/clp60651696
Google suggests that ramie will dye like cotton, so I am very tempted to buy it anyway and dye it. (Regularly do this with cotton garments.)
Has anyone actually dyed any ramie garments and can comment on the reality, please?