It is a good idea to wear cotton fabric in dark colours as they can give better protection against the sun's harmful ultraviolet (UV) rays.

A study was conducted by scientists in Spain and published in Industrial & Engineering Chemistry Research.

The researchers, led by Dr Ascension Riva of the Universidad Politecnica de Cataluna, dyed cotton fabric in a range of red, blue and yellow shades.

They used computers to estimate the levels of UV protection achieved with these shades, reported health website WebMD.

It was found that fabric with darker or more intense colours had better UV protection and yellow shades offered the least protection.

They suggested that clothing manufacturers use the study's findings to design clothing that provides better protection against harmful rays.

The researchers noted that it is not known exactly how colour interacts with other factors to influence a fabric's ability to block out harmful rays.

However, they said that numerous studies have concluded that lighter-coloured sportswear worn in the sun and in the tropics does not provide enough protection.

They said that "the colour of cotton woven fabrics is a factor that has a remarkable influence on their protection against ultraviolet radiation".

This article was first published in Mind Your Body, The Straits Times.