While there are people who strongly believe that ninjas wore all-black costumes with masks, which revealed only the eyes, historical facts and common sense does not support this myth.
The idea that ninja wore all-black costumes came from prop-handlers of the Kabuki theatre. The black costume was meant to allow prop handlers to blend with the background and look mundane as compared to the actors.
In reality, the ninja strove to look ordinary. Their lives depended on not drawing suspicion from others. They were masters at making use of societal stereotypes to look like commoners.
But! what about night missions? Wouldn’t stereotypical commoners still stand out sneaking around in the dark? True.
What then did the ninja wear for night missions?
Not All Black Costumes!
Even during the night, black would create an unnatural moving silhouette. It is believed that red or dark blue were better choices. In the dark, red wasn’t visible and if there was sudden light from the enemy’s lamp, the red would strike fear in the enemy due to the likeness of blood.
Furthermore, no ninja is going to wear black when sneaking around a snowy terrain. It would be a sure way to be detected and killed.
The fact is, the ninja of old Japan looked ordinary, and mundane. And they dressed appropriately for each mission, so as not to arouse suspicion. Admit it… An all-black costume in the midst of commoners in traditional clothing is more than a little suspicious.
However, go ahead and use all-black for your ninjutsu training. These are specially made for training purposes, unlike the ones for costume parties.
Photo retrieved from Flickr, at: http://www.flickr.com/photos/ir0cko/2455144185/