In this Skittles Rainbow kids’ science experiment, we used candy from my daughter’s Halloween stash to create a beautiful rainbow in a jar.  It was so easy and fun my 4 year old didn’t mind sacrificing a little bit of her candy in the name of science.

Follow the simple step-by-step below and then snag 30 more science experiments kids will beg to repeat in our shop!

Getting Ready

While my daughter rooted through her trick-or-treat bag for some Skittles, I quickly grabbed a few additional supplies:

  • 5 small glasses
  • a glass of hot water (hot but not scalding)
  • a tablespoon
  • A pipet or syringe

Skittles Science Experiment

When she returned with the Skittles, I had her begin by measuring out 2 tablespoons of hot water into each of the 5 glasses.

Awesome science activity for kids! Learn about density with this easy Skittles science experiment. {Playdough to Plato}

Next, I opened the Skittles and explained that each glass would have different color Skittles in them, but not the same number of Skittles in each glass. We chose to use:

  • 2 red
  • 4 orange
  • 6 yellow
  • 8 green
  • 10 purple

My daughter counted out the correct number for each color and placed them in the glasses of hot water.


NOTE: The hot water helps dissolve the Skittles quickly.  If you notice that the candies aren’t dissolving after stirring the candies, try microwaving the glass for 30 seconds to reheat the water.

Once the candy dissolved, we let the water cool to room temperature.  Cool water is more dense than warm water and we wanted all our glasses to be the same temperature.


While the liquids cooled, I asked my daughter some questions about this Skittles science experiment:

What color she thought had the most sugar in it?  She instantly pointed to the glass with the purple Skittles.

What color was the most dense? (Which one had the most sugar molecules in it?) Again, she pointed to the purple.

I  had her put the colors in order from most dense (purple) to least dense (red).

Next, I asked my daughter if she thought the most dense or least dense solution should go on the bottom of the rainbow jar.

“The purple goes on the bottom because the most dense sinks to the bottom,” she replied.  So I passed her a clean baby food jar and a pipet and she carefully transferred the purple sugar water to the jar.


I took over adding the remaining layers starting with green, then yellow, then orange and ending with red.

My daughter’s pipette worked really well to slowly dribble the colored water down the side of the glass. If you try pouring the different colors in, they will mix leaving you with a jar of muddy brown sugar water. If you don’t have a pipette, you can use a syringe and slowly dribble the sugar water down the inside of the jar.


Even with using a pipette and adding the liquid slowly, we could still see the less dense layer move down into the lower layer and then rise back up again.  My daughter liked to sit and watch the less dense layer “pop” back up to its own color.

Once all the layers were added, we placed the jar in the window and admired the colors as the sun shone through them.  I asked if she thought the colors would stay separate forever.

“No,” she said, “they will all mix together.”  She was right!  After a few days, the Skittles science experiment rainbow looked like a muddy puddle.

Much like real rainbows, the Skittles rainbow should be admired while you have the chance!

The Science Behind It

Each glass had the same amount of water but a different amount of sugar (Skittles) so the solution layers from least dense (the red water that had only two Skittles) to most dense (the purple water that contained ten Skittles).

Find More

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  1. Definitely can raise the age for this . As it would be fun for the younger ones , older children can actually do the work and understand the concepts as to how and why

    1. Yes, Sabine!
      So many different ages can enjoy this activity!
      Ashley // Happiness Ambassador

    2. Would this be considered a heterogeneous mixture or homogeneous mixture ?

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