Ultra-SiMPLE
xc=xpixels()/2
yc=ypixels()/2
f=250.0
Do k=0 To 500
   line color (rainbow(5*k))
   ellipse (xc, yc-4, 4*f, 2*f, k*0.05)
   f=f/1.0125
   delay (10)
Loop
wait quitkey