Dye some Epsom salts all the colours of the rainbow and keep them on hand for use in bath bombs, shower melts, sensory play and a whole host of other projects.
Put Epsom salts in a zip-lock bag with a couple of drops of colouring, zip it shut and shake, shake, shake!No need to squeeze the air out of the bag before you zip it shut, I find it works better with a lot of air inside for the salts to move around in.
Feel free to add more colour until you reach the desired hue.
Keep your Coloured Epsom Salts stored in the zip-lock bags until you need them.