Robot.getPixelColor returns invalid value when translucent frame overlaps other frame.

JDK/JRE tested: 1.8.0_b106 (32/64 bits)
OS/architecture: Windows 7
Graphics: Intel
Reproducible: Always
Is it a Regression: No
Is it a platform specific issue: Yes

To reproduce use attached file.
Expected behavior:
getPixelColor returns color which is different from blue.
Actual behavior
This method returns blue color.