MACROMEDIA FLASH 8-USING FLASH Use Manual page 240

Invert
inverts the base color.
Alpha
applies an alpha mask.
Alpha blend mode requires that a Layer blend mode be applied to the parent movie clip.
You cannot change the background clip to Alpha and apply it because the object would
appear invisible.
Erase removes all base color pixels, including those in the background image.
Erase blend mode requires that a Layer blend mode be applied to the parent movie clip.
You cannot change the background clip to Erase and apply it because the object would
appear invisible.
To see examples of the blending modes, see
Blend mode examples
The following examples illustrate how different blend modes affect the appearance of an
image. Be aware that the resulting effect of a blend mode may be considerably different,
depending on the color of the underlying image and the type of blend mode you apply.
Original image
Multiply
240 Using Filters and Blends (Flash Professional only)
"Blend mode examples" on page
Layer
Lighten
240.
Darken
Screen