Table 4. Representative performance benchmarks for naturally dyed nylon.

Dye/colorant class	Nylon type	Processing route	K/S or color outcome	Washing fastness	Light fastness	Functional property	Durability evidence	Key trade-off	Ref.
Phenolic/quinonoid HRP pigments	Nylon 5,10; nylon 6	HRP/H2O2, mordant-free	K/S = 2.4–3.4	Acceptable in selected cases	Poor-limited	Zones 8.6/7.7 mm vs. E. coli/S. aureus	No bioactivity wash test	Mild route but low depth and weak photostability	32
Gallic acid/catechol + chitosan	Nylon 5,10	Ex situ or in situ templating	GA/CS K/S = 4.5; CA/CS = 3.0	Acceptable	Poor	15.1/15.03 mm zones	After 10 washes, 11.4/10.9 mm	Chitosan drives high activity; in situ unevenness	33
Rice-straw phenolics/flavonoids	Nylon 6	Mordant-free; plasma activation	K/S = 6.6 to 10.7	Good	Good reported	UPF = 72.6–79.9; DPPH = 39.6%	After 20 washes, UPF 69.0 and DPPH = 34.9%	Strong durable function; outdoor ageing absent	20
Annatto carotenoid	PA/elastane 95/5	pH control; soy milk	K/S = 30.41–191.40; uniform = 40.30	Grade = 5 in soy systems	Not reported	Orange shade	Alkaline soy gave grade 4 after 5 washes	Very high acidic depth but poorer levelness	57
Weld flavonoids + TiO2/alginate	Recycled nylon 6,6	Post-finishing	Yellow; b* up to 17.7	Not fully reported	Up to 5	UPF up to 311	No laundering durability	UV/light gain; nanoparticle release untested	35
Microbial prodigiosin	Silk/PA66	pH-controlled nano pigment	K/S = 3.9; purple–red	Good	Limited	77.8% antibacterial; UPF = 15.1	No repeated laundering	Functional color but weak durability evidence	36
Luteolin flavonoid	PA56	Direct dyeing; Al/Fe coordination	Uptake = about 98%; yellow–brown	4 or above after coordination	Improved	UPF = 205; ABTS = 99%; 70%/95% antibacterial activities	After 10 washes, UPF ∼155 and ABTS above 60%	Excellent function but uses metal coordination	97
Olive-leaf phenolics	PA6	Exhaust dyeing; optional Cu	K/S = 18.60–20.09	Excellent in many samples	Weaker than wash	UPF = 45; Cu gave 98.10% C. albicans reduction	Functional wash durability absent	High K/S; Cu adds metal burden	132
Babool bark tannins	Nylon fabric	Mordant-free exhaust	K/S = 7.3 at pH 2	Good-excellent	4	UPF = 87.622; extract zones = 22/18 mm	No functional wash durability	Good UV and wet fastness; moderate light fastness	59
Spent coffee melanoidins	Nylon 6,6	Mordant-free; cassava tannin option	K/S = 3.18–3.32	Good-excellent	1/2–2	More than 99.9% S. aureus and 99.2–99.6% E. coli reductions; UPF = 177.53	No functional wash test	Excellent initial function but poor light fastness	140
Sea buckthorn leaf phenolics	Nylon/PU tricot	pH and concentration control	ΔE up to 47.12	Good-excellent	1–2 to 2	99.8–99.9% microbial reductions; UPF above 400 to 764.1	No retention after washes	Outstanding UPF but very weak light fastness	72
Bio-indigo/indigoid	Nylon	Bio or reduction-oxidation dyeing	K/S = 6.8–13.5; blue–green	4–5 to 5	4–5 to 5	Color-focused	No repeated wash cycles	Strong fastness; limited functional data	80
Alizarin anthraquinone	PA66	Supercritical CO2 dyeing	ΣK/S = 52.9–102.3	Shade changed after washing	1–2 after 40 h	Deep shade	Severe light fading	High depth did not equal durability	68
Bambusa vulgaris flavonoids	Nylon 6	Cu/Sn/Fe mordants	K/S = 4.2 directly; 8.6 Fe	Improved	6–7 or 7	Coloration	No repeated washing	Excellent photostability requires metal salts	133
Scrophularia + AgNPs	PA6 knit	Extract with Ag ions/NPs	K/S = 4.1–5.6	Good	8	100% E. coli/S. aureus reductions	After 10 washes, 79–88% retained	Durable antimicrobial but Ag release unknown	173
Turmeric/madder/catechu/indigo	PA56	Natural dyes; aloe gel post-mordant	K/S = 14.51–19.76 selected	Good	3–5 after aloe	Color-focused PA56 comparison	No long-term function	PA56 dyes well; light remains dye-dependent	70
Prangos + natural mordants	100% nylon	Carthamus, Terminalia, pomegranate	K/S = 9.40 Carthamus; 9.02 Terminalia	5	7–8 or 8	Color and light stabilization	Single-cycle fastness	Natural mordants can outperform metals; hue shifts	131
Kapok leaf extract	Nylon 6	Al/Cu/Fe pre-mordanting	K/S = 14.690 with Fe	Good	5 with Cu/Fe	UPF = 82.98; 92.63%/83.54% antibacterial; 94.42% antioxidant	No functional durability	Strong initial multifunctionality; metal/durability gap	135
Industrial plant dyes	PA interlock knit	Jet dyeing with catechu, madder, pomegranate, and mulberry	Commercial brown/red/pink/green shades	Good	1/2–3/4	Excellent UV protection	Repeated wash did not change L* significantly	Industrial relevance but weak light for some dyes	76
Curcumin smart dressing	PA6 fraction	1.0–1.5 g L−1 curcumin	Visible pH response; 1.0 g L−1 selected	4 at 1.0 g L−1	Not central	pH sensing; HaCaT compatible; hemolysis <2%	Washing/perspiration grade 4	Higher depth reduced fastness	106
Baicalin flavone	Nylon 6	Mordant-free exhaust	K/S = 7.8 at 8% owf; 4.1 at 3% owf	3–4 to 4–5	Not main limitation	UPF = 40+ before washing	UPF = 30 + after 5–30 washes; 26.12 after 50	Best UV durability; K/S decreased	47
Aspergillus turcosus pigment	PA6	Direct or alum; pH 4	K/S = 2.5; RUI 0.04	Alteration = 4; staining = 4–5	3–4	Antibacterial, antioxidant 45%, UPF = 15, pH response	After 20 washes, zones retained with ∼32% loss	Broad function but modest UPF/light fastness	44
Beta vulgaris-derived azo dye	Plain PA	Mordant-free derivatives	K/S = 18.85 and 13.07 at 1%	3–4 to 4	6	82.59–91.84% microbial reduction; UPF = 25.175–27.0225	No functional wash durability	High depth/function; wash/wet rubbing moderate	177