Nail polish is a great way to express one’s personality and individuality. From simple one-color affairs to more elaborate paint jobs and patterns, the ends of our digits can broadcast nearly anything we want to the world.

Now, Canadian cannabis brand Mood Ring uses science to create a new form of self-expression for stoners through nail polish called Hippy Fingerz.

Building on research that shows the body secretes cannabinoids through the skin, Hippy Fingerz uses thermotropic crystals to change color depending on the level of one’s high, purple haze (up to 5mg), blue dream (5-10mg), and grass green (+10mg). Trippy Nailz is durable, breathable, non-toxic, animal cruelty-free, vegan, and sustainable.