I would guess a semicolon. It is common for a semi-colon to be succeeded by a word like "however" or "therefore" and then a comma.
Red is the adjective. Adjectives are describing words so by saying that the truck is red, your describing what color the truck is.
C. Holmes lets him go free, because there wasn't enough of a case.
Oxymoron<span> is a figure of speech in which two opposite ideas are joined to create an effect. </span>
