Walking Colours

How can we mix colours without touching them?We found a way in Te Kakano.  Mrs Johnson put seven clear plastic cups out.  We  poured a different coloured  dye in  four cups  and water in three cups .  We folded paper towels and placed one in each cup making sure the paper touched each other.  Slowly the dye travelled (absorbed) up the paper towels and then down into the next cup.  New colours began to appear.  I wonder what these new colours were?
After the experiment many of our learners began experimenting with the paints and creating new colours.