Dreams of grey neither black nor white, grey is somewhere in between. You are unsure about how you feel; you are on the fence feeling confused and murky. Grey matter represents your brain, mental process, logic and thinking. T his dream is giving you the message that you need to organize your thoughts systematically so that you can make a decision.... Strangest Dream Explanations
(.1) The colour grey may represent old age, death, depression.
(2) As intermediate between black and white, and as the colour of mist, grey may symbolize an unclear state of mind where distinctions are blurred, or where you have difficulty in seeing where you are going or have lost all sense of direction.
(3) It may - as in grey fog - represent the unconscious. See also Fog.... A Dictionary of Dream Symbols
Strangely, a greyhound is a symbol of triumph if it was not running, but to dream of a running greyhound is a warning that you have bitten off more than you can chew and an alteration in your future plans would be advisable.... The Complete Guide to Interpreting Your Dreams