CTextColor

cTextColor (unofficial name) is a section in the executable of Super Mario Galaxy and Super Mario Galaxy 2 that allows text files to retrieve special color modifications.
The game applies a multiply-blend calculation to the stored color values, ending up in slightly darker effective colors.

Super Mario Galaxy

Color	Stored value				Effective value				Example
	R	G	B	A	R	G	B	A
Default/Black	FF	FF	FF	FF	-				-
Red	DC	82	82	FF	BE	42	42	FF	Every hundred years, a comet appears
Green	50	AA	50	FF	19	71	19	FF	in the skies above the Mushroom Kingdom.
Blue	50	8C	D2	FF	19	4D	AD	FF	The comet was so large one year, it filled the skies
Yellow	EB	C8	00	FF	D9	9D	00	FF	and sent countless shooting stars raining down.
Purple	B4	6E	C8	FF	7F	2F	9D	FF	The Toads brought the shooting stars to the castle,
Light Red	FF	BE	BE	FF	FF	8E	8E	FF	where they became a great Power Star.
Light Green	6E	F3	46	FF	2F	E8	13	FF	It should have been a very happy time
Turquoise	78	FF	FF	FF	38	FF	FF	FF	for the citizens of the Mushroom Kingdom.
Yellow	FF	FF	50	FF	FF	FF	19	FF	That was the night of the Star
Pink	FB	BC	FA	FF	F7	8B	F5	FF	Festival, held once every hundred
Grey	BE	BE	C8	FF	8E	8E	9D	FF	years to celebrate the comet.

Table locations:

Region		Address	Size
SMG1	USA	0x805BEC1C	0x30
	JPN
	PAL
	KOR	0x805D3334
	CHN	0x8072D608

Super Mario Galaxy (Korean)

The korean version of SMG has a slightly modified copy of cTextColor right below the standard one. The responsible code checks if the language is Korean and will apply the modified table if true.

Color	Stored value				Effective value				Example
	R	G	B	A	R	G	B	A
Default/Black	FF	FF	FF	FF	-				-
Orange*	E6	A0	00	FF	CF	64	00	FF	그해 버섯왕국에는
Green	50	AA	50	FF	19	71	19	FF	하늘이 안 보일 정도로 커다란
Blue	50	8C	D2	FF	19	4D	AD	FF	「별똥별」이 떨어졌습니다.
Yellow	EB	C8	00	FF	D9	9D	00	FF	백 년에 한 번 찾아온다는
Purple	B4	6E	C8	FF	7F	2F	9D	FF	그 「별똥별」에서
Light Orange*	FF	D2	50	FF	FF	AD	19	FF	많은 별들이 땅으로 떨어졌습니다.
Light Green	6E	F3	46	FF	2F	E8	13	FF	키노피오 친구들이 별을 성으로 가져왔고
Turquoise	78	FF	FF	FF	38	FF	FF	FF	별은 커다란 파워스타로 다시 태어났습니다.
Yellow	FF	FF	50	FF	FF	FF	19	FF	그날은 버섯왕국 사람들에게
Pink	FB	BC	FA	FF	F7	8B	F5	FF	행복한 추억이 될 수도 있었습니다.
Grey	BE	BE	C8	FF	8E	8E	9D	FF	백 년에 한 번, 하늘이 주는 선물에 감사하는 『별 축제』의 밤…

* Used to be red in the standard table.
Table locations:

Region		Address	Size
SMG1	KOR	0x805D3364	0x30
	CHN	0x8072D638

Super Mario Galaxy 2

For unknown reasons SMG2 holds an identical copy of each color within the same table.

Color	Stored value				Effective value				Example
	R	G	B	A	R	G	B	A
Default/Black	FF	FF	FF	FF	-				-
Red	DC	82	82	FF	BE	42	42	FF	Now, let me tell you
Green	50	AA	50	FF	19	71	19	FF	a new story
Blue	50	8C	D2	FF	19	4D	AD	FF	that also begins with stardust...
Yellow	EB	C8	00	FF	D9	9D	00	FF	Shimmering stardust
Purple	B4	6E	C8	FF	7F	2F	9D	FF	falls on the Mushroom Kingdom
Orange	FF	A0	64	FF	FF	64	27	FF	once a century.
Grey	BE	BE	C8	FF	8E	8E	9D	FF	That time had come again...
Red	DC	82	82	FF	BE	42	42	FF	Dear Mario,
Green	50	AA	50	FF	19	71	19	FF	Would you like to
Blue	50	8C	D2	FF	19	4D	AD	FF	share some cake
Yellow	EB	C8	00	FF	D9	9D	00	FF	while we watch
Purple	B4	6E	C8	FF	7F	2F	9D	FF	the shooting stars?
Orange	FF	A0	64	FF	FF	64	27	FF	Meet me at the castle!
Grey	BE	BE	C8	FF	8E	8E	9D	FF	Peach

Table locations:

Region		Address	Size
SMG2	USA	0x806F22AC	0x3C
	JPN	0x806F1A8C
	PAL	0x806F79AC
	KOR	0x806F10EC
	TWN	0x806F254C