For others to have a blue means to have a fight with someone
And oddly, and I know this from first-hand experience, a red-haired person will be called bluey, or less pleasing either carrot top or blood nut. I used to ignore those people who used those expressions, except for my father-in-law.
You can do something until you are blue in the face, which means do it without result until exhaustion, another way of saying you’re wasting your time.
And if something comes out of the blue, it usually means it’s entirely unexpected. For me, that’s always a bill I wasn’t expecting, for someone else an inheritance.
And in some parts of the world, blue is used as a synonym for a conservative political party, for insistence, the Liberal party in Australia, and the Democrats in the United States
Blue should not be confused with the word blew, which is the past tense of the blow, which is wind causing an air current or blowing air through pursed lips.
That doesn’t mean that if something blew up it was just a giant air mass exploding because it can’t. If a bomb blew up it means it detonated.
And if that sounds complicated:
What if something blew my mind? Does that mean my head exploded? No, it just means it’s incomprehensible, whether good or bad.
Or
What if I blew a fortune on a three-legged horse? We all throw good money after bad, but you can quickly lose a fortune, or blew it.
It’s the same thing with opportunities, for instance, he had a chance and blew it. Yes, obviously something better came along, not, or he just ignored a sterling opportunity.