Color change and staining

One of them is a shelf problem and the other is a complaint, and they have different causes.

Two separate problems

The product changing color, which looks like spoilage.

The product coloring something it was used on, which is a returned product and an angry customer.

Color changing in the bottle

Dye fading in light, which is why a clear bottle on a sunny shelf is a decision.

Dye reacting with an oxidizer, which bleaches it, sometimes within days.

pH-sensitive dyes shifting hue as the formula drifts, which is actually useful information badly presented.

And yellowing from a raw material oxidizing, which is often the fragrance rather than the dye.

Any of them reads to a customer as the product having gone bad, whether or not anything else has changed.

Staining in use

The one that costs money. A colored cleaner marking grout, a light worktop, a cloth, a carpet or a hand.

Porous and light-colored surfaces are where it shows, and it is worst when the product is left to dwell rather than wiped off, which is exactly what instructions often tell people to do.

Test it properly: a soak rather than a wipe, on grout, unsealed stone, white cloth, plastic and skin, and leave it long enough to be unfair.

Preventing both

Use dyes intended for cleaning products, at the lowest level that gives the color.

Check stability against your oxidizer, your pH and light before committing.

Consider not coloring it at all, which removes both problems and is increasingly what the market expects from a product positioned as simple.

And where color is kept, put a dwell-and-rinse instruction on the label that reflects the staining test rather than the cleaning test.

References