#include <Ninja.h>
void  njSetBackColor( color0, color1, color2 )
Uint32  color0
Uint32  color1
Uint32  color2

njSetBackColor( 0xff0000ff,0xff0000ff,0xff000000 );
while(1) {
  njDrawLine2D( ... );
  ....
  njWaitVSync();
}