once it fades there's really no bringing it back. the color is throughout the material and it is not likely engineered with any light fastness properties to it. Red is the worst. you see it in some cars.. it will fade to pink over time. packaging materials are the same way (my industry) it's costly to engineer into product colorants. short life items like bags and boxes, kart bodies, kid toys do not have it, but items like building signage (big coke logo) its built in so the sign will hold the color for a long time.