blue, blew

Blue or blue means the color of the sky, or of denim jeans--
The baby's blue eyes may turn to brown before he is a year old.
Blue jeans are so common that most people wear them sometimes.
Blue may also mean sad--
"I'd rather be blue, thinking of you, than be happy with somebody else."
"Blue, blue, my world is blue..."

Blew or blew ( rhymes with blue ) is the past tense ( yesterday, or some time ago ) form of "blow", meaning to move by force of air, to explode or demolish, or the movement of air or wind--
The explosion blew a hole in the side of the building.
He sat in a chair all day and blew smoke rings.
The house was full of strange noises when the wind blew. 

Now that you know that, you can say--
"When they blew soap bubbles, some looked blue, and some looked pink."
"The engine sputtered and blew blue smoke."

Note--"blue" also means pornographic, as in "blue" movies, or obscene, as in "blue" language--
The network censor inserted a bleep in place of his occasional blue language.