Not only philosophical, it can come out in the code too. I've written a number of testing packages over the years, and it's a rare testing platform that can assert that some sort of test failure assertion "correctly" fails without some sort of major hoop jumping, usually having to run that test in an isolated OS process and parse the output of that process.

This isn't a complaint; it's too marginal and weird a test case to complain about, and the separate OS process is always there as a fallback solution.

You want both. To test green and red pixels.

"Task failed successfully!"