We've already talked about the joys of getting shiny with a simple gloss , but it can do way more. If you don't want to commit to a hue, glossing is the way to go. A gloss will wash out on its own, allowing you to try a richer or more-vibrant shade — without roots in a few weeks. (One thing to note: Since this is adding color, not lightening with bleach, you can only go darker or brighter.) If you gloss, those results typically last six weeks, which gives you enough time to figure out your next move.