If we had a blue city with one black disease cube due to an outbreak and we pull that blue city card during epidemic infection phase, is it an outbreak? We thought that 3 was the max #of cubes one city can have (even if they are of different colors), but I just read one of the thread here that mentioned a city with 2 red cubes and 2 black cubes, total of 4 cubes in one city.
An outbreak only occurs due to cubes of a single color:
If the city already has 3 cubes of this color, do not place a 4th cube. Instead, an outbreak of this disease occurs in the city (see Outbreaks below).
And therefore a city can have up to three cubes of each color, not just three cubes overall:
As a result of outbreaks, a city may have disease cubes of multiple colors on it; up to 3 cubes of each color. This does not affect infections.