I have a pptx file with a single shape. Setting it to 70% transaprent I can compare the pptx and see the only difference is in /ppt/slides/slide1.xml
<a:solidFill>
<a:schemeClr val="accent1">
<a:alpha val="40000"/>
</a:schemeClr>
</a:solidFill>
Anyone have any idea how on earth "70%" translates to "40000"?
It seems different for me. My alpha values seem to use this function:
y = -1000x + 100000
Where x is the percentage and y is the alpha value. I recommend you do the same (figure out a function based on your computer and verify them) and not worry about it.
It seems each single percentage unit corresponds to 1000 of these alpha units.
