This is what Auto Express had to say about these great bulbs from Autolamps
'Blue bulbs designed to mimic the intense blue-white light of HID gas discharge headlights are popular as replacements. The coating that gives the blue-white look robs a little light, but this pair from Autolamps strikes a good compromise. It matched the plus 50 per cent VisionPlus in the light tunnel. Bigger brand names were close to matching its performance, but none could get close to that super price. The pack also includes two blue sidelight bulbs to complete your carís lighting makeover.'