try Dylon Eco Reactive Dye which can be purchased online at most major online supermarkets and independent crafts stores. You’ll need a white t-shirt or light piece of clothing, avoiding using a ...

By adding blue dye to white clothes that appear yellow or gray ... I found that the two thicker shirts of the batch, a Uniqlo T-shirt and a Zara tank top, looked brighter and whiter more quickly ...