Cimmerian shades refer to darkness, gloom, or obscurity. Antonyms for this phrase would be bright, light, or sunshine. It is used to describe a dark, depressing atmosphere, so antonyms could include words that suggest a happy, lively environment such as cheerful, pleasant or radiant. The phrase can also be used to describe uncertain or unclear situations, so antonyms could include words like clear, apparent or evident. The term can be used metaphorically to signify mental states like melancholy or confusion, and antonyms could be composed of words like joy, clarity or stability.