Table 3: Palette index
Color format
All sprite palettes are defined in bank $FD and the palette table is located at $FD:5FEE.
The sprite palettes consist of  16 colors, of which index 0 is always transpalent. Therefore, palette data in actual ROM defines 15 colors except this.

Color definition is done in RGB555 format handled by PPU. This format can express 32768 colors by specifying each color of red, green, and blue with 5 bit (32 gradations).
RGB value are allocated from the lower bits of the 16-bit word.
To comvert to the RGB888 format, normalize each component as follows:
public static System.Drawing.Color Rgb555ToRgb888 (ushort rgb555)
{
    // Get each color
    int red = rgb555 & 0x1F;
    int green = (rgb555 >> 5) & 0x1F;
    int blue = (rgb555 >> 10) & 0x1F;
    // Normalize each color
    red = (red << 3) | (red >> 2);
    green = (green << 3) | (green >> 2);
    blue = (blue << 3) | (blue >> 2);
    return System.Drawing.Color.FromArgb(255, red, green, blue);
}
Public Shared Function Rgb555ToRgb888(rgb555 As UShort) As System.Drawing.Color
	' Get each color
	Dim red As Integer = rgb555 And &H1f
	Dim green As Integer = (rgb555 >> 5) And &H1f
	Dim blue As Integer = (rgb555 >> 10) And &H1f
	' Normalize each color
	red = (red << 3) Or (red >> 2)
	green = (green << 3) Or (green >> 2)
	blue = (blue << 3) Or (blue >> 2)
	Return System.Drawing.Color.FromArgb(255, red, green, blue)
End Function

Note: Since some legacy softwares or emulators don't normalize, colors may be a little dark in a 24-bit color environment.
Palette list
ID Address Content ID Address Content
00
6682
General purpose pallet1[*1]
01
6484
Diddy (1P)
02
6664
General purpose pallet[*2]
03
6B8C
Coin/ Golden barrel
04
6574
Dixie (1P)
05
66A0
Squitter
06
66BE
Wooden box[*4]
07
646DC
Klomp
08
66FA
Kannon
09
6718
Hook/ Iron bal
0A
6636
Bonus cannon (Black)
0B
6772
Shuri (Orange)
0C
6790
Kruncha (Blue)
0D
67EA
Rattly
0E
6808
Lockjaw
0F
6826
Squawks
10
6862
Click-Clack (Purple)
11
6880
Splash
12
689E
Kutlass (Yellow)/ Klank (Yellow)
13
6428
Diddy and Dixie icon (1P)
14
68BC
Coin/ Golden barrel
15
6754
Bonus cannon (Green)
16
68F8
Green gradation[*3]
17
6916
Goal
18
6934
Baloon (Red)
19
6952
Baloon (Green)
1A
6970
Baloon (Blue)
1B
68DA
Animal sign
1C
698E
Neek
1D
69AC
Cat O' 9 Tails
1E
69CA
Mini-Necky
1F
6A06
Klobber
20
6A24
Krow's egg
21
6A60
Krow (Head)
22
6A42
Krow (Body)
23
7528
Funky
24
7898
Klank (Orange/ Brown)
25
7546
Surfboard[*5]
26
6A7E
Clanky
27
6ABA
Rollercoaster
28
6B8C
Coin/ Golden barrel
29
78B6
Klank (Pink/ Green)
2A
6AD8
Kaboom
2B
7166
Explosion/ Kleever's hand and fire ball
2C
7564
K.Rool's Letter
2D
6AF6
Shutter
2E
6B14
Ghost rope
2F
6B32
Kaboing (Glay)
30
6B6E
Gate
31
6BAA
Airplane[*3]
32
6BC8
Puftup's needle
33
705A
Radio
34
7292
Funky's barrel
35
7184
Race flag
36
71A2
Signal (Off)
37
6A9C
Swanky
38
6C04
Zinger/ King Zing (Yellow)
39
79C4
Forest Bonus Wall
3A
6C40
Klinger
3B
6C5E
Flitter
3C
6C7C
Flotsam (Blue)
3D
6C9A
Flotsam (Yellow)[*3]
3E
62DC
Ship deck Bonus Wall
3F
62FA
Hive Bonus Wall
40
6318
Forest Bonus Wall
41
765A
Lava splash
42
7678
Splash
43
6D12
Rambi
44
6D30
Flitter (Body: green Wing: blue)[*3]
45
6D4E
Flitter (Body: purple Wing: blue)[*3]
46
6D6C
Flitter (Body: purple Wing: green)[*3]
47
6D8A
Flitter (Body: brown Wing: purple)[*3]
48
6BE6
Zinger/ King Zing (Red)
49
6CF4
Glimmer
4A
67AE
Kruncha (Pink)
4B
6C22
Zinger(Green)[*3]
4C
67CC
Kruncha (Red)
4D
6B50
Kaboing (Green)
4E
6CB8
Flotsam (Red)[*3]
4F
6CD6
Flotsam (Green)
50
6DA8
Spiny
51
6DC6
Kleever (Normal, red)
52
6E02
Mist
53
6E20
Klampon
54
6844
Quawks
55
785C
Krook
56
787A
Klockhead (Green)
57
6DE4
Kleever (Deep red)
58
6E5C
Cat O' 9 Tails
59
6E7A
Leaf
5A
6E98
Hot baloon
5B
6EB6
Chest (Black)
5C
6ED4
Kloak
5D
6EF2
Airplain wing and propeller
5E
62A0
Klubba's club
5F
62BE
Klubba
60
6F4C
Engurde
61
69E8
Kreepy Mini-Necky
62
6F10
Kleever (Pale red)
63
6F2E
Kleever (Srightly deep red)
64
6E3E
Klockhead (Brown)
65
6F6A
Klobber (Yellow)
66
6F88
Klobber (Black)
67
6FA6
Bonus Token[*3]
68
6FC4
DK Coin[*3]
69
6FE2
K.Rool
6A
7000
K.Rool's Gun
6B
701E
K.Rool (Black)
6C
703C
Guitar
6D
7078
Klank (Blue/ Purple)
6E
6242
Cloud/ Rain
6F
7096
Clapper
70
70B4
Spark
71
721A
Gas (Blue)
72
7238
Gas (Red)
73
7256
Gas (Purple)
74
7274
Iron ball debris
75
72B2
Yoshi
76
72D0
Mario
77
70EE
Screech
78
6336
Tower Bonus Wall  (Left)
79
6354
Tower Bonus Wall  (Right)
7A
6372
Lava Bonus Wall
7B
6390
Ship hold Bonus Wall
7C
63AE
Ice cave Bonus Wall
7D
63CC
Forest Bonus Wall  (Right)[*3]
7E
63EA
Forest Bonus Wall  (Right)[*3]
7F
6408
Forest Bonus Wall  (Right)[*3]
80
7800
Diddy and Dixie icon (2P)
81
6446
Link
82
7910
Kreepy Krow (Head contrast: 2/3)
83
792E
Kreepy Krow (Body contrast: 2/3)
84
794C
Kreepy Krow (Head contrast: 1/2)
85
796A
Kreepy Krow (Body contrast: 1/2)
86
7988
Kreepy Krow (Head contrast: 2/5)
87
79A6
Kreepy Krow (Body contrast: 2/5)
88
NULL
Undefined
89
NULL
Undefined
8A
NULL
Undefined
8B
NULL
Undefined
8C
NULL
Undefined
8D
NULL
Undefined
8E
NULL
Undefined
8F
NULL
Undefined
90
72EE
K.Rool (contrast: 2/3)
91
730C
K.Rool (contrast: 1/2)
92
732A
K.Rool (contrast: 2/5)
93
7348
K.Rool's Gun(contrast: 2/3)
94
7366
K.Rool's Gun(contrast: 1/2)
95
7384
K.Rool's Gun(contrast: 2/5)
96
73A2
Kudgel
97
73C0
Kudgel's club
98
74B0
King Zing (Pale red)
99
74CE
King Zing (Slite pale red)
9A
74EC
King Zing (Deep red)
9B
750A
King Zing (Deep red)
9C
73DE
King Zing
9D
73FC
King Zing
9E
741A
King Zing
9F
7438
Kleever (Normal, bright)
A0
7456
Kleever (Normal, dark)
A1
7474
Kleever (Normal, slightly bright)
A2
7492
Kleever (Normal, slightly dark)
A3
7582
Wrinkly
A4
75A0
Wrinkly's book
A5
763A
Boss level icon
A6
7696
Unknown
A7
76B6
Unknown
A8
76D4
Donkey
A9
76F2
Fish
AA
6426
Diddy and Dixie icon (1P)
AB
6464
Klomp/ Klubba icon
AC
774C
Flying Krock debris
AD
75FA
Clanky and Wrinkly icon
AE
761A
Funky and Swanky icon
AF
776A
Mud
B0
7148
Shuri (Pink)
B1
712A
Puftup (Blue)
B2
7710
Snapjaw
B3
772E
Ship hold Bonus Wall (Red)
B4
7788
Kutlass (Green)/ Klank (Black/ Green)
B5
77A6
Tire
B6
77C4
Iron ball
B7
77E2
Click-Clack
B8
78D4
Kreepy Krow (Head)
B9
78F2
Kreepy Krow (Body)
BA
710C
Puftup (Green)
BB
NULL
Undefined
BC
NULL
Undefined
BD
NULL
Undefined
BE
NULL
Undefined
BF
NULL
Undefined
C0
7820
K.Rool
C1
783E
Splash
C2
NULL
Undefined
C3
NULL
Undefined
C4
NULL
Undefined
C5
NULL
Undefined
C6
NULL
Undefined
C7
NULL
Undefined
C8
NULL
Undefined
C9
NULL
Undefined
CA
NULL
Undefined
CB
NULL
Undefined
CC
NULL
Undefined
CD
NULL
Undefined
CE
NULL
Undefined
CF
NULL
Undefined
D0
6682
General purpose pallet1[*1]
D1
6682
General purpose pallet1[*1]
D2
6682
General purpose pallet1[*1]
D3
6682
General purpose pallet1[*1]
D4
6682
General purpose pallet1[*1]
D5
6664
General purpose pallet2[*2]
D6
6664
General purpose pallet2[*2]
D7
6664
General purpose pallet2[*2]
D8
6934
Baloon (Red)
D9
6952
Baloon (Green)
DA
6970
Baloon (Blue)
DB
68BC
Coin/ Golden barrel
DC
68BC
Coin/ Golden barrel
DD
68BC
Coin/ Golden barrel
DE
68BC
Coin/ Golden barrel
DF
68BC
Coin/ Golden barrel
E0
68BC
Coin/ Golden barrel
E1
68BC
Coin/ Golden barrel
E2
6718
Iron ball
E3
68BC
Coin/ Golden barrel
E4
68BC
Coin/ Golden barrel
E5
68BC
Coin/ Golden barrel
E6
68BC
Coin/ Golden barrel
E7
68BC
Coin/ Golden barrel
E8
68BC
Coin/ Golden barrel
E9
6682
General purpose pallet1[*1]

Notes
*1: Used for bananas, KONG letters, text, label of DK barrel, etc.
*2: Used for barrels, cannon barrel, wooden box, animal box, chest.
*3: Unused.
*4: Unused. Actual use is General purpose pallet2.
*5: Unused. Actual use is Dixie (1P).