var t1 = just.animate({
   targets: "#target",
   duration: 4000, 
   props: {
      d: {
         value: [
            'M3 22v-20l18 10-18 10z',
            'M12 4.248c-3.148-5.402-12-3.825-12 2.944 0 4.661 5.571 9.427 12 15.808 6.43-6.381 12-11.147 12-15.808 0-6.792-8.875-8.306-12-2.944z',
            'M21 6.285l-11.16 12.733-6.84-6.018 1.319-1.49 5.341 4.686 9.865-11.196 1.475 1.285z', 
            'M4 0l16 12.279-6.951 1.17 4.325 8.817-3.596 1.734-4.35-8.879-5.428 4.702z',
         ], 
         interpolate(left, right) {
            return flubber.interpolate(
               left, 
               right, { maxSegmentLength: 0.3 }
            )
         }
      },
      fill: {
         value: ['black', 'red', 'blue',  'hsl(128, 50%, 50%)'],
         interpolate: just.mix.colors
      }
   }
})    

t1.play({ repeat: Infinity, alternate: true });

just.tools.player(t1);