There are tons of products you can buy which are designed to keep the colour where it is, and not let colours run into each other, some are better than others of course, but there are also some natural ways of keeping on top of this as well.
Do you have items in your wardrobe that are looking a little tired? That cold shoulder top perhaps? Maybe you have fabrics that are bobbling for example? Maybe your favourite top has a couple of pulled threads in need of attention? Or maybe you’ve just re-stocked on a few things and want to make sure they last as long as possible?