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Color Key Keyword
<ColorKey>
<ck>
<TransparentBG>
<tbg>
Switch to turn on color keying when moving a bitmap. A
graphic frame with this switch set will examine the color of the top left pixel of the bitmap and when adding that graphic to the displayed frame all pixels of that color will not be copied. Enables the use of a transparent background, handy if you have changed the background color or your bitmaps do not have a white background.
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