Dark and Light in "The Lone Ranger and Tonto Fistfight in Heaven"

I noticed that in "The Lone Ranger and Tonto Fistfight in Heaven" there is a lot of imagery of darkness.  For example, the protagonist visits the 7-11 during the "graveyard-shift," or extremely late at night.  Because he notices the clerk's uneasiness, he toys with him by saying things like, "Hot enough to make you go crazy."  He also asks for a slushie, for which the clerk would have to turn around, giving the protagonist the prime opportunity to shoot and rob the 7-11.

I believe he does these things because he is under the cover of darkness.  He can feel stronger and grasp at power when he is in the comfort that darkness offers.  Another example is when he mentions that he would often break lamps during fights with his girlfriend.  She started out buying replacements, but then stopped, and they would "argue in the dark."  The author immediately follows up this statement with the main character's girlfriend throwing an insult at him, saying he is drunk and stupid just like his brother, to which he responds, "My brother don't drink that much."  This is clearly a jab back at her.  In this statement he sarcastically acknowledges that he is a drunk and, through the use of his poor grammar, that he is stupid.  Because he is under the protection of the darkness of the room, he feels more able to be audacious.  He also mentions, "At three in the morning I could act just as young as I wanted to act.  There was no one around to ask me to grow up."  Again, because he is out and about while it is dark, he feels more like himself.

These images reciprocate the feelings he has of his own skin color.  As a Native American, he has darker skin.  It makes sense, then, that when he is in darkness, he feels more able to be himself.  (Perhaps this is why he returns to the reservation...to be around other Native Americans and the "darkness" of their skin.)  However, instances of identity acceptance do not occur during the daylight hours of the story.  When it is light out, i.e., when he has to mingle with other white Americans, he feels powerless.  When he plays a caucasian in basketball who, in the protagonist's words, "needed to be beaten by an Indian, any Indian," he loses to the white boy.  It is a testament to how the narrator feels about his life as a Native American, and how he feels like he cannot do anything, especially nothing better than a caucasian can.  These images of dark and light are clearly metaphors for the main character's own inability to accept his Native American identity at all times.