Red noteheads

They won't print red, they just indicate being out of the professional range of the instrument

They are outside the range of the instrument.
These red notes are not printed, they are only used to indicate that you have left the range.
Of course, you can switch off the message or use a larger range:

• disable Edit -> Preferences -> Note Input -> Color notes outside of usable pith range
• in Staff/Part Properties modify the borders of usable pitch range