Christopher describes some of the reasons why he hates the colors yellow and brown. Mr. Forbes thinks that hating colors is silly, but Siobhan points out that everyone has favorite colors. Christopher compares his hatred for certain colors to all the arbitrary choices people make in life.
A group of words that includes a subject and a verb but does not express a complete thought is called subordinate clause, or also referred to as dependent clause. This group of words is not a sentence and can't stand alone as a sentence. Example : Because I can't wait for the bus; Until the sun rises.