"Cry blues" is an idiomatic expression that means to feel sad or depressed. The antonyms for this expression would be words that convey the opposite emotion. Words like "happy," "cheerful," "joyful," "elated," and "content" would be fitting antonyms for "cry blues." When someone is feeling "happy," they are experiencing a sense of pleasure or contentment, which is the direct opposite of feeling "blue." Similarly, being "cheerful" and "joyful" means to experience feelings of optimism, positivity, and a sense of well-being, which is a stark contrast to the emotions that "cry blues" represents.