Rule 86 - The Highway Code

Daylight riding. Make yourself as visible as possible from the side as well as the front and rear. You could wear a light or brightly coloured helmet and fluorescent clothing or strips. Dipped headlights, even in good daylight, may also make you more conspicuous. However, be aware that other vehicle drivers may still not have seen you, or judged your distance or speed correctly, especially at junctions.