MACROMEDIA FLASH 8-ACTIONSCRIPT 2.0 LANGUAGE Reference page 351

Integer value String value
8
"add"
9
"subtract"
10
"invert"
Illustration Description
Adds the values of the
constituent colors of the button
to those of its background, and
applies a ceiling of 0xFF. This
setting is commonly used for
animating a lightening dissolve
between two objects.
For example, if the button has a
pixel with an RGB value of
0xAAA633, and the background
pixel has an RGB value of
0xDD2200, the resulting RGB
value for the displayed pixel is
0xFFC833 (because 0xAA +
0xDD > 0xFF, 0xA6 + 0x22 =
0xC8, and 0x33 + 0x00 = 0x33).
Subtracts the value of the
constituent colors in the button
from those of the background,
and applies a floor of 0. This
setting is commonly used for
animating a darkening dissolve
between two objects.
For example, if the button has a
pixel with an RGB value of
0xAA2233, and the background
pixel has an RGB value of
0xDDA600, the resulting RGB
value for the displayed pixel is
0x338400 (because 0xDD -
0xAA = 0x33, 0xA6 - 0x22 =
0x84, and 0x00 - 0x33 < 0x00).
Inverts the background.
Button 351