Colouring Agent/Pigment

CI 16255

Reviewed by Kate · Last updated 14 Aug 2026

A synthetic red colourant used to add visual appeal to skincare formulations

Best For Skin Types

All

Usage Frequency

As directed by product instructions

What Is CI 16255?

CI 16255, commonly known as Ponceau 4R, is a synthetic azo dye approved for use in cosmetics and personal care products. It belongs to a class of colorants that have been used across food, beverage and cosmetic industries for decades. In skincare formulations, it serves purely as a cosmetic colorant to create red and pink tones in products such as serums, creams and masks.

The ingredient does not provide active skincare benefits; its function is aesthetic only. It is used at very low concentrations in skincare products and is distinct from colour additives used in food or animal feed applications.

How It Works

CI 16255 is a water-soluble synthetic dye that disperses throughout a formulation to produce colour. It does not interact with skin cells or alter skin behaviour in any meaningful way. Once applied, it sits on the skin surface as part of the product matrix and is removed during cleansing.

Clinical Evidence & References

CI 16255 has a long history of regulatory approval and use in cosmetics. Safety assessments conducted for its use in animal feed and other applications have found it to be well-tolerated at permitted concentrations. However, direct clinical studies investigating its use specifically in skincare products are limited in the published literature.

Allergic reactions to synthetic colorants in general are considered rare, though they may occur in individuals with known sensitivities to azo dyes. Current evidence suggests adverse reactions are uncommon at the concentrations used in cosmetic formulations.

How to Use

There are no special usage guidelines for products containing CI 16255. Use formulations containing this ingredient according to the product instructions. If you have a known sensitivity to azo dyes or synthetic colorants, perform a patch test before wider application or consult a dermatologist.

Safety & Precautions

CI 16255 is approved for cosmetic use and considered safe at permitted concentrations. Those with documented sensitivity to azo dyes should exercise caution.

Frequently Asked Questions

From the Clinic

Not sure what your skin actually needs?

Two minutes, a few questions, and we’ll point you at what matters — no guesswork.

Take the skin quiz

Learn More About Skincare Ingredients

Explore our comprehensive ingredient glossary to understand what's in your products.

Browse All Ingredients

Authorised Stockist

Official UK retailer

Tracked Delivery

Free UK shipping over £50

5 Star Rating

Trusted by thousands

Expert Advice

Free consultations