%!PS-Adobe-2.0
%%BoundingBox: 0 0 250 250

% animate.ps

/build-square {
0 0 moveto
1 0 lineto
1 1 lineto
0 1 lineto
closepath
}
def

/page-setup {
125 125 translate
72 dup scale 
1 72 div setlinewidth
} def

% - the animation begins ------------------------------------------

% - the square rotates and so do the colors

/A 0 def

{

gsave

page-setup

A rotate
1 0 0 setrgbcolor
newpath
build-square
fill
0 setgray
newpath
build-square
stroke

grestore
showpage

/A A 5 add def

} loop