Washington, Oct 15 Wearing blue and red clothing is a better way to avoid the sun's harmful ultraviolet (UV) rays, say Spanish scientists.

Ascensión Riva and colleagues have said that the same cotton fabric dyed deep blue or red provide greater UV protection than shades of yellow.

Their study could lead to fabrics with better sun protection.

The researchers explained that the colour of a fabric is one of the most important factors in determining how well clothing protects against UV radiation.

However, there are gaps in scientific knowledge about exactly how colour interacts with other factors to influence a fabric's ability to block ultraviolet protection factor (UPF).

The scientists used of computer models that relate the level of UV protection achieved with three fabric dyes to their effects in changing the UPF of fabrics and other factors.

In doing so, they dyed cotton fabrics in a wide range of red, blue, and yellow shades and measured the ability of each coloured sample to absorb UV light.

Fabrics with darker or more intense colours tended to have better UV absorption.

Deep blue shades offered the highest absorption, while yellow shades offered the least.

Clothing manufacturers could use information from this study to better design sun-protective clothing, the scientists indicate.

The study has been published in an upcoming issue of ACS' Industrial and Engineering Chemistry Research, a bi-weekly journal. (ANI)