Also the colors differ between adobe and the viewer: Have a look at the transparent red in the lower right corner of the attachments.

Thanks for the sample. I'll see what I can do.

I can't do much about the colour difference in the pink/red transparency as I'm pretty sure this is related to how the composites are applied in Java.

The graphic in the bottom right has a content stream as defined below

/GS1 gs
0 w
0 0 0 RG
1 0 0 rg
6.91 7.54 m
6.91 135.07 l
93.43 135.07 l
93.43 7.54 l
6.91 7.54 l
f
Q
q
/GS2 gs
0 w
0 0 0 RG
1 0 0 rg
11.94 77.86 m
11.94 130.14 l
54.78 130.14 l
54.78 77.86 l
11.94 77.86 l
f
Q
q
/GS3 gs
0 w
0 0 0 RG
1 0 0 rg
39.18 28.82 m
39.18 93.15 l
77.72 93.15 l
77.72 28.82 l
39.18 28.82 l

The graphics state /GS1 and later commands paint the large pink/red and the following two graphic states /GS2 and /GS3 specify two more boxes with a transparency of 0. We apply the zero transparency but it doesn't cause the cutout effect that adobe does. I changed the composition rule to use the SRC_OUT rule to get the cutout effect with a alph = 0.