How much may I customize a Fog Cloud spell?
  
 
     
     
             
                 
 
 
         
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 The description for the fog cloud  spell says:      You create a 20-foot-radius sphere of fog centered on a point within range. The sphere spreads around corners, and its area is heavily obscured.    Is it possible for my wizard to cast a green fog cloud during a battle against goblins, and later in the same day cast a red fog cloud when fighting orcs? This would signal to a distant observer what the opponents are in the area.   If I know my opponent lost his family to a cloudkill  spell, may I create a fog cloud  that has yellow-green fog like the cloudkill  spell? Or if my opponent fears a magical violet mist with gold sparks, may I cast a fog cloud  with those effects?   My intent here is to understand the limits of the existing spell.      
 
         
             
                 dnd-5e spells 
             
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