MACROMEDIA FLASH 8-ACTIONSCRIPT 2.0 LANGUAGE Reference page 350

Integer value String value
6
"darken"
7
"difference"
350 ActionScript classes
Illustration Description
Selects the darker of the
constituent colors of the button
and those of the background (the
ones with the smaller values).
This setting is commonly used
for superimposing type.
For example, if the button has a
pixel with an RGB value of
0xFFCC33, and the background
pixel has an RGB value of
0xDDF800, the resulting RGB
value for the displayed pixel is
0xDDCC00 (because 0xFF >
0xDD, 0xCC < 0xF8, and 0x33 >
0x00 = 33).
Compares the constituent colors
of the button with those of its
background, and subtracts the
darker of the two constituent
colors from the lighter one. This
setting is commonly used for
more vibrant colors.
For example, if the button has a
pixel with an RGB value of
0xFFCC33, and the background
pixel has an RGB value of
0xDDF800, the resulting RGB
value for the displayed pixel is
0x222C33 (because 0xFF -
0xDD = 0x22, 0xF8 - 0xCC =
0x2C, and 0x33 - 0x00 = 0x33).