An idea: 

1: Obtain cat who is relatively casual about liquids, very large sheet of paper, cat toy, food coloring, and at least one baking tray with edges.

2: Spread paper over floor, place tray in center, fill with food coloring. 

3: Gently place cat in tray, get feets colored. 

4: Dangle toy into food coloring, then haul it away, leaving a trail on the paper and hopefully luring the cat. 

5: Proceed to lure cat back and forth across the paper with the toy, occasionally going through the tray again in order to keep feets and toy colored. 

6: Art of cat chasing toy. 

7: Profit.