Dyeing method

Colourimetric value

K/S

L*

a*

b*

C*

ΔE*a

at 400 nm

at 550 nm

(a) Undyed

73.4

4.16

26.8

27.2

?

3.26

0.318

(b) Redissolution with O2

62.5

6.30

38.1

38.7

15.8

18.1

0.756

(c) Sequential without O2

59.5

12.6

45.8

47.5

25.0

21.3

0.961

(d) Sequential with O2

59.6

16.1

50.7

53.2

30.1

19.7

0.966

(e) Simultaneous Oxidation without O2

59.7

9.85

37.7

38.6

18.1

14.2

0.953

(f) Simultaneous Oxidation with O2

58.4

16.9

53.9

56.5

33.4

22.9

1.06

(g) Post-Oxidation with O2

54.4

18.7

37.7

42.1

26.2

12.1

1.56