Researchers believe they have found a solution to makeup for darker skin tones often appearing ashy or grey once applied.
In recent years the market for beauty products designed for people with darker skin tones has boomed, with some brands now offering consumers a huge variety of shades.
Now researchers say they have found a way to create redder tones in makeup for darker skin, finding the addition of ultramarine blue reduces the ashy or grey appearance such products can create.
Gabriella Baki, associate professor of pharmaceutics at the University of Toledo, said that while some companies already use the additive in their products, its use is not widespread.
“We hope that our research provides new insights into why it should be added,” she said.
The team note that the ashy complexion that can arise from makeup foundations for darker skin is down to such products typically containing larger quantities of black iron oxide.
“Ultramarine blue creates redder and yellower hues, which is different from black iron oxide,” said Baki. “By creating warmer hues, the foundation looks more skin-like. Additionally, ultramarine blue has a lower refractive index than black iron oxide.” Baki added that this creates less opaque colour, which also helps to reduce what is known as the “grey cast”.
The new work, which has yet to be published but is to be presented at the spring meeting of the American Chemical Society (ACS), reveals how the team looked at the impact of including ultramarine blue by creating 20 powder foundations and 18 stick foundations in both darker and lighter shades.
The researchers analysed the colour of the powders using a spectrophotometer, as well as assessing them visually both on specialised paper and when applied to the inner forearms of participants.
Baki added that ultramarine blue helps in both darker and lighter foundations by enabling the creation of different undertones, but can be transformative for the former because it reduces the grey cast.
“Based on our research, we recommend combining black iron oxide and ultramarine blue. However, ultramarine blue can be used alone as a dark pigment as well. It depends on what skin tone and undertone needs to be achieved with the foundation,” said Baki.
“For very dark skin colour, ultramarine blue may not be enough to match consumers’ skin tone value, as it creates lighter foundations when compared to black iron oxide at the same percentage. If a dark colour needs to be created, combining black and blue can provide a more skin-like colour than black iron oxide alone.”
The study provides examples of how to create more inclusive foundation lines for consumers. “Ultramarine blue should be added to foundations for all shades to expand the undertones for the same shade and create more skin-like foundation shades,” Baki said.
