He collaborated with researchers from cosmetic giant Chanel's R&D division dedicated to skin related issues and facial appearance.
In one study, Professor Russell and his team measured images of 289 faces ranging in age from 20 to 70 years old, and found that the ageing process makes the lips, eyes and eyebrows paler, while surrounding skin becomes darker.
This results in less contrast between the features and the surrounding skin - leaving older faces with less contrast than younger faces.
The difference in redness between the lips and the surrounding skin decreases, as does the luminance difference between the eyebrow and the forehead, as the face ages.
Although not consciously aware of this sign of ageing, the mind uses it as a cue for perceiving how old someone is, the research claims.
"The kind of contrasts that decreased was the contrast between the facial features - the lips, the eyes and the eyebrows with the surrounding skin," Dr Russell said.
"So, for example, we found that the redness of the lips decreases with ageing, but the skin that surrounds the lips actually becomes more red, so the redness contrast between lips and the rest of the face decreases with age and that certainly is something that can be manipulated with make-up."
To confirm this hypothesis, the researchers carried out a further study involving more than a hundred subjects in Gettysburg and Paris, in which they artificially altered these facial contrasts using a computer.
They found that increased contrasts led observers to perceive faces as younger, while when they artificially decreased contrasts the faces appeared older.
Professor Russell's findings appear in a study in the open access journal PLoS ONE.
- DAILY MAIL