Overview L'Oreal Paris Preference gives you bold, luminous colour full of reflects, that lasts up to 8 weeks. 100% Grey Coverage. Discover the unique shades of Preference with light-reflecing dyes for a more luminous colour. The translucent gel formula, associated with the new shine oil, gives your hair a colour with luminous reflects and intensifies the natural nuances of your hair colour. The Shine Protect Conditioner is enriched with a UV filter and Vitamin E to preserve your shine and colour for up to 8 weeks.