In runescape, you can't.
Chromatography-This is when you put dye on a piece of special paper and put it in some water. When the water is soak up the dye will separate.
Chromatography
To separate dye into blue ink, you would need to use a process called chromatography. This involves dissolving the ink in a solvent and allowing it to separate based on the different properties of the dye molecules. The blue dye will travel at different rates along the chromatography paper, allowing you to isolate it as a distinct color.
red cloth dye should do the trick
The Phoenicians were famous for their purple cloth and they used shellfish for their purple dye in order to dye the cloth which is created only for the robes of the kings. hope this can help :)
mix red and blue dye Red dye- redberries blue dye- woad leaves
to dye the cloth you have got
blue
Cloth,cotten,fabric,dye
I think what would happen is that the cloth would not keep it's colors after washing since salt makes the dye stick to the cloth.
Dye them blue with a blue dye you can buy at Wal-Mart maybe?
because blue dye is better than red