University of St Andrews researchers monitored diet in 35 people, finding more colouration in those eating more greens.
Other research suggests these changes may make you more attractive.
Other scientists said the study, in the PLoS One journal, might not fully reflect the link between consumption and appearance.
It has been known for some time that certain yellow and red pigments called carotenoids found in many types of fruit and vegetables, can have an effect on skin tone.
However it is not clear exactly how much influence a normal healthy diet can have on this effect.
The St Andrews scientists recruited 35 students, mostly white, who were quizzed on their fruit and vegetable intake over a six week period.
The volunteers were told not to use sunbeds, fake tan or make-up.
An instrument was used to analyse their skin tone before, during and after the test period.
The results suggested that changes in fruit and vegetable consumption might be related to changes in skin tone, with more fruit and vegetables contributing to a deepening of natural red and yellow skin colouration.
Earlier research by the team had found links between the perceived attractiveness of faces and even subtle changes in these skin tones.
“It is possible that even smaller dietary changes are able to produce perceptible benefits to skin colouration,” they wrote.
However, they did concede that the effects on older people might be different, and that more research into non-white volunteers would be needed.
Dr Glenys Jones, from the Medical Research Council Human Nutrition Research laboratory at Cambridge University, said that another issue was that food preparation techniques made a big difference to how much of the carotenoids were available from food, and the study did not take this into account.
She added: “With the vast majority of the population not consuming the recommended five-a-day of fruits and vegetables, this could be another way of encouraging people through our own innate vanity to increase fruit and vegetable intake.
“After all fruits and vegetables contain a wide range of nutrients that are good for not just for our complexion, but for our overall health.”
Dr Catherine Collins, a dietician at St George’s Hospital in London, said that although people heavily exposed to sunlight were excluded from the study, all the areas of skin studied were those exposed to daylight, and the effects of this could not be ruled out.
However, she echoed the point that anything which encouraged people to eat more fruit and vegetables was a good thing.
“For the rest of us post-university people, it’s another potential reason to carry on eating your greens – and red/orange/yellow veggies as well.
“The grown-up way of serving them cooked, or as part of an overall meal along with other foods, boosts bio-availability of these useful phytochemicals, which may contribute to overall health – as well as beauty!”