Evaluating the Effectiveness of Colour Retention Hair Care Products Via Spectral Analysis

At a time when over 75% of women report dyeing their hair, hair care products formulated to improve colour retention are growing in popularity. Image Source: Flickr user Faylyne

There was a time when dyeing your hair was considered so taboo that women were driven to extreme lengths to guard their beauty secret. They would slink into salons via back entrances and receive colour treatments in private booths, emerging with rejuvenated locks they passed off as natural. That changed when Clairol released the first at-home commercial hair dye in 1956, followed by a clever and memorable marketing tagline: “Does she … or doesn’t she?” Within a decade, the proportion of women who dyed their hair skyrocketed from 7% to 50% and hair dye sales increased from $25 million to $186 million.1 Nearly 60 years later, 75% of women and nearly 10% of men report artificially changing their hair colour,  and the biggest concern faced by those of us with dyed tresses isn’t stigma or fear of discovery, but preserving the colour we love. In response, shampoos, conditioners, and hair treatments formulated to optimize colour retention are increasingly entering the marketplace and represent one of the fastest growing segments within the hair care industry. Spectral analysis allows hair product manufacturers to objectively evaluate the efficacy of their formulations to improve colour protection and create products that meet consumer expectations.

Thoughtful formulation of hair products can improve colour retention and guard against premature fading. Image Source: Flickr user frankieleon

Protecting Against Colour Fading

The premature fading of dyed hair colour is a frustrating experience primarily caused by colour wash-out as the result of shampooing. In response, hair product manufacturers have developed formulas that seek to decrease the wash-out rate of dyes and improve colour retention by using surfactants and conditioning agents that protect against colour fading. The formulation of these products requires thoughtful and informed design to create a balance of colour protection, cleaning ability, conditioning properties, and sensory experience. This may be particularly challenging in shampoo formulation, as the most popular cleansing agents are anionic surfactants containing sodium laureth sulfate (SLS) and sodium lauryl ether sulfate (SLES). Although these are effective and economical agents that produce the rich lather most customers expect from shampoos, they are also prone to stripping colour from dyed hair. Choosing a milder anionic or a different surfactant type can improve colour retention performance. If SLS and SLES are used, researchers have discovered that introducing an amphoteric co-surfactant such as cocamidopropyl can be used to minimize colour loss.2 Additionally, conditioning agents such as cationic and specialty silicone polymers can significantly improve colour retention as well as offer additional sensory, aesthetic, and protective benefits. However, the chemical and physical properties of these conditioners must be considered to ensure compatibility with other ingredients, particularly organic materials such as natural waxes, oils, or butters.3 Particular conditioning agents may be used synergistically with certain surfactants to fortify colour retention efficacy and enhance produce performance.

Bleached and damaged hair is particularly prone to colour wash out as the result of shampooing. Image Source: Pexels user Adrianna Calvo

Evaluating Colour Retention Using Spectral Analysis

To evaluate the efficacy of both individual colour retention ingredients and hair product formulations, an objective basis of colour measurement must be employed to accurately quantify product behavior. Spectral analysis using spectrophotometric instrumentation is considered the gold standard in hair colour analysis and is the first choice for evaluating colour change in response to shampooing, conditioning, or treatment. Spectrophotometers are ideally suited for providing objective colour data to precisely identify even slight colour variations and allow you to develop a fully articulated picture of a product’s functionality. By taking baseline measurements of newly dyed hair samples and comparing them to measurements after each washing, conditioning, or treatment event, you can clearly track colour changes and observe the rate of colour loss over time to correlate colour changes to specific individual ingredients or test the efficacy of a completed product. As a result, you can more precisely tailor formulations to enhance colour retention as well as produce accurate, evidence-based claims to market your product.

HunterLab Colour Measurement

HunterLab spectrophotometers are world-renowned for their sophisticated design, extraordinary accuracy, and user-friendly designs. With a complete range of portable, benchtop, and in-line instruments to choose from, we have the tools you need to evaluate your formulas in a range of environments and obtain the critical colour data you need to optimize product performance. Contact us to find out more about our extraordinary products, outstanding customer support services, and why HunterLab is the first name in colour measurement.