Hitachi VTUX6430A - Manual (Page 34)

ON: The screen becomes blue and mutes sound when a channel without a broadcast signal on the VCR or a
channel on which broadcasting has finished.
• If the signal is too strong, this function may not operate even if you specify <ON>. During
playback this function does not operate.
OFF:
The AUTO BLUE feature is switched off.
5 Press the GUIDE button to end the setting.