Levity means inappropriate behavior or sincerity. It is a six-letter word in the dictionary beginning with L, which can mean unsuitable humor.
levity
No colour means humorous. You're possibly thinking of off-colour humour, which is generally tasteless or racist humour, or blue humour which is vulgar humour, littered with profanity. There is no actual colour associated with general humour.
it means leader
amity
acacia
inquisitive
abase
It simply means, not suitable or not fit.
monotonous
heavy
This may be a typo as it is only one letter shy of misalliance, which means an unsuitable or unworkable marriage or alliance.
vastly