Asymptote: Transparency causes strange color rendering in Adobe Acrobat

Question

I noticed that using transparency in a picture that's compiled as vector graphic output (render=0, no PRC) leads to strange colors (they look paler and desaturated) when the resulting picture is viewed with Adobe Acrobat (I use version X). When I view the output PDF with SumatraPDF everything looks fine. An Example:

size(10cm,0);

path cle=unitcircle;

draw((-2.5,0)--(2.5,0),linewidth(10mm));
filldraw(shift((-1.5,0))*cle,magenta+opacity(.5));
filldraw(shift((-0.5,0))*cle,green+opacity(.5));
filldraw(shift((0.5,0))*cle,red+opacity(.5));
filldraw(shift((1.5,0))*cle,blue+opacity(.5));

shipout(format="pdf");

On the left hand side you see the picture viewed with Adobe Acrobat and on the right hand side you see the picture viewed with SumatraPDF.

When I leave out the opacity settings everything looks fine:

I encountered such an issue before when using opacity in a picture created by TikZ and think the problem might be connected to that (There seems to be some trouble with transparency groups in Adobe Acrobat). Here is a way to solve this problem in a TikZ picture. How can the coloring issue be solved in Asymptote?

Answer 1

I can see this difference between Adobe Reader XI(v11.0.5) and SumatraPDF v2.3.2, but only when Adobe Reader setting Edit->Preferences->Page Display->Default Transparency Blending Color Space is set to Working CMYK. When it is set to Working RGB, the pictures looks almost identical.

Answer 2

My informed guess is that you are experiencing the same problem described earlier in the context of TikZ here (including solutions): Using opacity in TikZ causes strange rendering in Acrobat.

Perhaps that solution can be adapted to use with Asymptote. In any case, if you include your graphics into a LaTeX document, and use one of the solutions in the other thread, the embedded graphics should be displayed correctly.