Colors on screen different in Adobe Acrobat (and Reader) and in Browser

When I open a PDF in Adobe Acrobat (same in Reader) the colors are displayed differently (and "false) compared to opening the SAME PDF in the Browser using the plugin.

I cannot find any Settings in Acrobat that change the display. It is a RGB PDF, exported from InDesign and we have used the same colour profile throughout.

Here is a screenshot. Since it's a PNG the effect is lest drastic than on the screen. On the screen Acrobat makes the blue circle look like pure Cyan.

Is there a setting anywhere that we missed?