Current colors.

#define DIFFSTATE_REMOVED_DEFAULT_BG			RGB(255,100,100)
#define DIFFSTATE_REMOVEDWHITESPACE_DEFAULT_BG		RGB(255,100,100)
#define DIFFSTATE_ADDED_DEFAULT_BG			RGB(255,255,0)
#define DIFFSTATE_ADDEDWHITESPACE_DEFAULT_BG		RGB(255,255,0)
#define DIFFSTATE_WHITESPACE_DEFAULT_BG			RGB(180,180,255)
#define DIFFSTATE_WHITESPACE_DIFF_DEFAULT_BG		RGB(255,255,0)
#define DIFFSTATE_EMPTY_DEFAULT_BG			RGB(200,200,200)
#define DIFFSTATE_CONFLICTED_DEFAULT_BG			RGB(255,0,0)
#define DIFFSTATE_CONFLICTADDED_DEFAULT_BG		RGB(255,100,0)
#define DIFFSTATE_CONFLICTEMPTY_DEFAULT_BG		RGB(255,50,50)
#define DIFFSTATE_IDENTICALREMOVED_DEFAULT_BG		RGB(255,200,200)
#define DIFFSTATE_IDENTICALADDED_DEFAULT_BG		RGB(180,255,180)
#define DIFFSTATE_THEIRSREMOVED_DEFAULT_BG		RGB(255,120,200)
#define DIFFSTATE_THEIRSADDED_DEFAULT_BG		RGB(120,255,180)
#define DIFFSTATE_YOURSREMOVED_DEFAULT_BG		RGB(255,200,120)
#define DIFFSTATE_YOURSADDED_DEFAULT_BG			RGB(180,255,120)

COLORREF CLineDiffBar::m_BinDiffColors [10] = { 
	 RGB(0x00, 0xCC, 0x00),
	 RGB(0xff, 0x80, 0x00),
	 RGB(0x00, 0x66, 0xb3),
	 RGB(0xff, 0xcc, 0x00),
	 RGB(0x33, 0x00, 0x99),
	 RGB(0xcc, 0xff, 0x00),
	 RGB(0x00, 0x99, 0x99),
	 RGB(0xff, 0xb2, 0x00),
	 RGB(0xcb, 0xff, 0x00),
	 RGB(0x41, 0x00, 0x99),
};

Proposed line-diff colors.

COLORREF CLineDiffBar::m_BinDiffColors [10] = { 
	 RGB(0x00, 0x81, 0x00),
	 RGB(0x00, 0x8f, 0x00),
	 RGB(0x00, 0x9d, 0x00),
	 RGB(0x00, 0xab, 0x00),
	 RGB(0x00, 0xb9, 0x00),
	 RGB(0x00, 0xc7, 0x00),
	 RGB(0x00, 0xd5, 0x00),
	 RGB(0x00, 0xe3, 0x00),
	 RGB(0x00, 0xf1, 0x00),
	 RGB(0x00, 0xff, 0x00),
};

Proposed line-diff colors 2 (add some whiteness ==> more contrast?).

COLORREF CLineDiffBar::m_BinDiffColors [10] = { 
	 RGB(0x00, 0x81, 0x00),
	 RGB(0x00, 0x9d, 0x00),
	 RGB(0x00, 0xb9, 0x00),
	 RGB(0x00, 0xd5, 0x00),
	 RGB(0x00, 0xf1, 0x00),
	 RGB(0x14, 0xff, 0x14),
	 RGB(0x3c, 0xff, 0x3c),
	 RGB(0x64, 0xff, 0x64),
	 RGB(0x8c, 0xff, 0x8c),
	 RGB(0xb4, 0xff, 0xb4),
};