go to powerbulbs.co.uk you can get blue bulbs from philips or their own brand ones, the own brand ones are buy one get one free plus with orders over £10 you get free blue side lights.
they are replacement bulbs, which are blue and the blue glass acts like a filter onthe yellow light making it look white not yellow. and are a fair bit brighter than standard lights but you can get brighter yellow bulbs too. i have powerbulbs ownbrand 50% brighter bulbs and they are brilliant.
they bulbs are direct replacments.
however if you want the lights which are very bright and are either white or blue, and look especially blue if they go over a bump on the road. those are Xenon head lights, they are a completley different style of light and a bit more complicated. on clios the only legal way to have them is to fit renault xenon projector lights which are about £300 i think from a member on here, or install projector style after market lights then fit a HID kit (
www.hids4u.co.uk) the colour white to blue depends on what "heat" of bulb you get, the renault ones are 5300k, which are white, the bigger the number the bluer the light, so 8000k is verry blue looking. you can get HID kits for about £45, you can fit them to normal lights but they take a wee but of modding, but apprently they wont pass an MOT as they are too bright because of the clios reflector lenses. but hey they look good.