In my practice I prioritize natural dyes that have strong light and colorfastness. However each dye is unique and will age with use and time, just as the fiber itself will.
TIPS
Hand wash with pH neutral detergent (most eco-friendly brands fit the bill)
Avoid prolonged sun exposure
Avoid contact with anything acidic/citrus as it may alter the dye color or discharge it completely.
FUN FACT
Synthetic dyes have only been in use since 1856, meaning every colored textile created in the preceding 50,000 years were created using natural dye methods! Most synthetic dyes are toxic as heck and pollute our waterways and overall ecosystem.