colorfastness
nounUK /ˈkʌləfɑːstnəs/
US /ˈkʌlərfæstnəs/
Colorfastness means a cloth keeps its color and does not fade when you wash it.
The label says the shirt has good colorfastness, so it won't fade in the wash.
OTHER MEANINGS
2. The ability of a material to keep its color when exposed to sunlight.
Outdoor curtains need high colorfastness to survive bright sun.
3. The quality of a dye staying fixed to fibers during cleaning.
The factory tests colorfastness by washing samples many times.
4. Resistance of printed ink to rubbing off or bleeding.
Good colorfastness keeps the printed pattern sharp after many uses.