The white flag is at the same time neutral in terms of identity, but also symbolizes surrender as opposed to the struggle that apparently belongs to identity that does not want to be 'neutral'.
The irony is that in white all colors are hidden without any struggle.
Soldiers who showing a white flag in their hand should not be attacked. One expects a person wearing the white flag to remain neutral and obliged not to enter into warfare.
The white flag is known as a sign of surrender. For example, Islam means literally "surrender to God." Surrender as a counterpart of separation and distinction.
The colored flag and even the black flag create an 'own' identity and forms a means of binding a people, a group and symbolically distinguishing them from others. As soon as there is a fear of loss of identity, there is a need to preserve identity and identifications become more important See also the "je suis Charlie" which was massively deployed Facebook (on the photo and profile picture in the colors of the French flag).
A kind of symbolic identification with the victims who would stand for freedom, and the shared sense of the threat of losing freedom and a protest and a fight for its preservation. I see this reaction as a part of the spirit which focuses strongly the fear of losing identity and freedom.
