// init
PGraphics3 pg3 = new PGraphics3( 180,180,null );
pg3.defaults();
pg3.format = ARGB; // RGB works as supposed

// draw
pg3.background( #FFCC00 );
pg3.stroke( #FF0000 );
pg3.fill( #FFFF00 );
pg3.rect( 40,40,100,100 );

// main
size( 200,200,P3D );
background( #FFFFFF );
image( pg3,10,10 );