Gray Jedi in have a troubled history in the world of Star Wars, beginning with the definition of the term. A gray Jedi is not merely one who challenges the Jedi High Council or questions the Jedi Code. It's too broad and irresponsible to brand healthy curiosity and questioning as a gray Jedi. A gray Jedi goes beyond that through actions.
The term “gray Jedi” in Star Wars is somewhat of a misnomer, considering that the definition refers to one who is practically non-Jedi. That being said, quite a few Jedi can be placed into this category. But Mace Windu identified as a Jedi despite his possible inclusion in the "gray" category. Self-identification is indeed a factor in deterring gray Jedi status. However, there are other factors that can take precedence to disavow a Jedi status in light of certain behavior that could threaten stability or the authority of the Jedi High Council and the Jedi Code.
What It Means To Be A Gray Jedi In Star Wars
While the term “gray Jedi” has yet to be canonized onscreen, the category has been defined as one of two types of Force-users. The first identifies a gray Jedi as one that is capable of toeing the line of the Light and Dark Sides of the Force without being consumed by the Dark Side. Otherwise, that person would simply be Sith. The second definition encompasses Jedi who do not live or operate by the Jedi Code. These people are often considered rogue or renegade Jedi. Both, however, are untraditional Force-users. Their way with the Force, or lack of adherence to the way of the Jedi, supposedly makes them more susceptible to the Dark Side. Star Wars could use more gray Jedi onscreen to expound upon them and further diversify Force-sensitives and the types of Force-users in the universe.
A Sith can also be "gray" in a similarly oxymoronic way. A Sith who does not hold themselves accountable to the Jedi or Sith, or who possesses a balanced control over both sides of the Force, could be called a gray Jedi whether they fight for the Light or Dark side. Gray Jedi are also Force-users who do not identify as Jedi and Sith. Gray Jedi are wayward Force-users, which makes them inherent threats to either organization should they become an official Jedi or affiliated Sith. Many characters in the Star Wars universe feel that gray Jedi simply can’t be trusted.
But it is important to note, only one applied definition is sufficient to be deemed a gray Jedi. It is possible, though rare, for both definitions to be applied. There are few Jedi who can maintain control in balancing the Dark and Light Sides of the Force, like Master Windu. It would seem by the first definition that Mace Windu would technically be considered a gray Jedi. However, his adherence to the Jedi Code and use of mostly, if not only, techniques of the Light Side of the Force makes the fan-favorite Mace Windu a true Jedi. That is, until Star Wars: Revenge of the Sith.
Why Mace Windu Is A Gray Jedi
Anakin insisted Mace Windu follow the Jedi Code and have Palpatine stand trial, as this is the galactic due process. Granted, that advice runs contrary to Anakin’s own actions in killing a defenseless Count Dooku instead of arresting him to stand trial earlier in the film. This rogue Jedi moment for Anakin was one of the things that led him down the path to the Dark Side. And when Mace Windu confronted Palpatine and attempted to kill him, that was also a rogue Jedi act.
Mace Windu was prevented from taking Palpatine's life, thus launching his evil plans. But in this scene, his murderous intent in the name of securing peace qualifies Mace Windu as a gray Jedi. It is unlikely Mace Windu would have been disciplined for going against the Jedi Code. But even if he were suspended or had his rank revoked, Master Windu’s sense of justice and powerful use of the Force and lightsaber would likely have prevented him from actually adhering to such disciplinary actions. Besides, Master Windu was a Force-user too powerful for the Jedi to cast out of their ranks.
Had Mace Windu survived Anakin Skywalker's descent into villainy, he would probably still identify as a Jedi. It can be argued that one act, even if only an attempt, outside the Jedi Code is not enough to apply the second definition of a gray Jedi. But anyone with knowledge of Mace Windu's attempt on Palpatine’s life without due process would be wary of him as a threat to their civil rights.
Therefore, the blemish of going against the Jedi Code, even once as Anakin witnessed for himself, would brand Mace Windu as a Jedi not to be trusted. Such branding would then threaten the legitimacy of the Jedi Code and Jedi Order if the Jedi Master continued on with his rank and duties. This could open the path for other Jedi to either try mastering techniques of the Dark Side or disobeying the chain of command and Jedi Code. The risks of the Jedi Order devolving into anarchy due to the actions of a high ranking rogue Jedi are too great to ignore. That level of volatility, regardless of how Mace Windu identifies, would follow him as one of Star Wars most powerful gray Jedi.