My bath salts are orange-yellow, but they turned green when put into water. Why did this happen?

Okay, no problem. Regarding the color change of your bath salts, this is actually quite an interesting little chemical "magic trick," and I'm here to explain it to you.

Hey! Your Bath Salts Might Be Performing a "Color-Changing Trick" for You

Don't worry if this happens; it's usually a deliberate design by manufacturers to add a bit of fun, not a sign that the product has gone bad. The principle behind it is quite simple, much like playing with watercolors when we were kids.

The Core Reason: The Art of Color Mixing

Simply put, the orange-yellow color you see is likely not made up of a single pigment, but rather a mixture of multiple pigments of different colors.

One of the most common combinations is:

A large amount of yellow pigment
A small amount of blue pigment

When they are still dry, solid particles, your eyes primarily perceive the dominant yellow, mixed with a tiny bit of other colors, making the overall appearance orange-yellow or orange.

When Bath Salts Meet Water...

Once you drop the bath salts into the water, something magical happens:

Dissolution and Diffusion: The different colored pigment particles begin to dissolve and disperse in the water.
Re-mixing: The colors that were "crammed" together in the solid form now have the opportunity to mix thoroughly throughout the bathwater.
Color-Changing Magic: Based on what we learned in art class, yellow + blue = green. When these two pigments mix evenly in the water, they collectively present a new color—green!

So, what you're experiencing is actually a color-changing process from "physical mixing" to "solution mixing."

Is It Safe?

Absolutely, you can rest assured.

The pigments used in bath salts, bath bombs, and other bath products are strictly screened and tested, and must be skin-safe, cosmetic-grade pigments. This color-changing effect is a carefully designed selling point by manufacturers, intended to add some visual surprise and fun to your bathing experience.

Small Tip: If you're curious, you can check the bath salt packaging for the Ingredients list. There, you might see terms like CI 19140 (a yellow pigment) and CI 42090 (a blue pigment). These are the international standard names for pigments, and seeing them will confirm our hypothesis.

In short, go ahead and enjoy your "magic potion" bath! It's just a harmless and interesting little design.