White definitely leans toward the sinister in the world of Kamigawa. Take for example the excellent art of Samurai Enforcers, by artist newcomer Mitch Cotie:
Samurai Enforcers art by Mitch Cotie
The art description for the piece expresses the emotion here:
Location: inside the steets of a "white-aligned" village
Action: Show two or three human foot soldiers in the background being lead by a white samurai in the front. These troops serve as law enforcement and crowd control. They are marching through a crowd of peasants who reach up for help but only get pushed aside.
Focus: On the lead samurai and the foot soldiers' strength and callousness.
Everyone sees the tough samurai marching ahead on this 4/4 Bushido limited bomb. But note the subtle detail of the peasants being shoved aside in the soldiers' insistence on defense from the kami.
White is strong and protective, and it succeeds at preserving the peace. But it may sometimes do so at the cost of basic decency. Think about that the next time you hear someone call White Knight the "good guy" and Black Knight the "bad"!