English: A simulation of severe phase errors in PAL color decoding shown applied to a PM5544 test pattern. In this example the chroma delay line is enabled, cancelling out the phase errors and suppressing Hanover bars. The outermost columns of the test pattern contain color signals that do not alternate phase between lines unlike a normal PAL signal; if the phase is correct those signals will have complementary color from line to line, and cancel out if a delay line is present. In this case, they reveal the phase error through discoloration.