Not a black day
Be in the black = have money in one’s bank account.
A black day (for someone/something) = an unhappy day when something bad or sad happens.
Black ice = ice that is almost invisible on roads and therefore very dangerous.
A black list = a list of persons who are considered to be dangerous/disloyal, etc.
A black mark = a mental or written record of someone’s misconduct, failure, etc.
A/the black sheep (of the family) = a person whose conduct is considered to be a disgrace to the family or the group.
A black spot = a place on a road where accidents often happen; a problem area, e.g., with high unemployment, crime, violence, etc.
In someone’s black books = out of favour with someone.
In black and white = in writing or in print. Often used to state that something is legally binding.
Not as/so black as one/it is painted = not as bad as people generally say....