The following test fails intermittently. This was reported on macOS, but given the failure, it is likely not to be platform-specific.

JDK8130122Test > testEmptyShapes FAILED
    junit.framework.AssertionFailedError: expected:rgba(0,128,0,255) but was:rgba(255,255,255,255)
        at test.robot.testharness.VisualTestBase.assertColorEquals(VisualTestBase.java:173)
        at test.robot.scenegraph.JDK8130122Test.lambda$testEmptyShapes$3(JDK8130122Test.java:104)