Idioms with colours

Florencia was feeling blue because she had an argument with her best friend Michaela. All the fight began for just white elephants, the day before Florencia´s fifteen party, a red letter day for her. They couldn’t stay together for more than a minute, and they put each other in their own black list.
The friends couldn’t understand Florencia´s and Michaela’s attitude so, they arranged all the situation a few hours before the big party, and that day began everybody’s blue day.
A few hours before the party was ending, Michaela show to Florencia her apologies in black and white by a letter. At first her friend was a little yellow streak, but then she admitted that she have done a mistake too.

red letter:a very important day
Blue and blue day: sad and favourite
Black list: to be angry with someone and remember waht he done all the time
white elephants: things useless.
yellow streak:to be cowar.
black and white :to writte something down.

social studies upperintermediate in town.