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Wednesday, May 26, 2021

How to Make a Skittles Rainbow

Skittles famous advertising slogan is taste the rainbow, but did you know you can also use skittles to make a rainbow? In this post I'll show you exactly how to turn Skittles into a magical rainbow in seconds. If your kids love rainbows then they'll love this simple science experiment that's perfect to do at home or in the classroom. 

skittle rainbow up close


The beauty of this science experiment is that it can be set up really quickly and only requires 2 {edible} ingredients. Most kids can even set it up and complete the experiment themselves, as long as they can be trusted not to eat all the Skittles while doing it.

If you theme your activities the skittles rainbow is a great experiment to do during science week, a candy science theme, rainbow theme or to coincide with St Patrick's day {which is why I included it in my March play calendar}.

Supplies needed to make a Skittles rainbow

  • Skittles
  • Shallow plate
  • Warm water
  • Glass or cup

For our experiment we used 3 mini snack sachets of Skittles {to get an even number of each colour}, about a 1/4 cup of water and a small side plate. If you use a dinner plate you'll need more Skittles to fill the edge and the rainbow will take a little longer to appear.
items needed to do the skittles rainbow experiment


1. Arrange skittles in a circle around the edge of the plate. You can put them in any colour order you like, but if you want an even rainbow then repeat the same pattern all the way around.

skittle rainbow pattern on the plate

In the classic Skittles pack there are five fruit flavours: lemon {yellow}, orange {orange}, strawberry {red}, green apple {green} and grape {purple}. We arranged ours yellow, orange, red, purple and green all the way around.
skittles lined in rainbow order around a plate
If you have younger kids who want to do the experiment themselves and want to lay the Skittles colours haphazardly, don't worry it will still create the same rainbow effect. You could also group all the colours together so all red, all orange, all green etc to create a thick colour wheel style rainbow. Or use two colours to practice patterning creating AB or even AAB, ABB patterns.

There are also other Skittles flavour packets which include different colours and flavours including pink, blues, different purples and greens. These are mainly available from boutique confectionary stores or online.

2. Slowly pour water into the centre of the plate. If you pour it too fast the skittles may float out of place which will distort the rainbow. A few seconds after the water reaches the edge, the rainbow will start to appear.

pouring water over skittles on a plate to create a rainbow
skittles rainbow starting to appear
My 7yr old poured the water onto the plate for our experiment and then the girls eagerly waited for the rainbow to appear. At first they didn't think it was working because it didn't appear instantaneously, however it quickly started forming after a few seconds. Straight away the girls starting saying wooooow it's doing it and look it's magic.

If you watch the video below you'll see our rainbow appear in real time. It went slightly off centre as I didn't realise our plate was on a slight lean.

skittles rainbow from above

My kids are naturally inquisitive so of course they picked up the Skittles to see what they looked like after the rainbow had formed. As you can see from the photo below, the surface area of the Skittles where the water touched is completely white as all of the colour has dissolved.

skittles after the colouring has dissolved into water

The million dollar question though, and one my kids were only too happy to find the answer to, is - can you still eat the Skittles? Yes you can still eat the skittles after the experiment is finished, and they even taste the same without colour, although it might be harder to know which flavour is which.


Although the rainbow appearing from the Skittles looks like magic, there's actually a physical change taking place that can be explained by science. The coloured shell of each Skittle is a mixture of food colouring and a sugar coating which quickly dissolves when placed in water. The sugar molecules in the Skittles disperse into the water, which is visible due to the food colouring.


Why do you use warm water?

Warm water absorbs the colour from the Skittles faster as the water molecules move around faster in warm water vs cold water. 

Why does the rainbow go towards the centre of the plate?

This is due to concentration gradient. The Skittles colours diffuse through the water from the point with the highest concentration of sugar {the Skittle itself} outwards to the point of least concentration {the plain water in the centre of the plate}.

Why don't the Skittles colours mix together?

The amount of sugar dissolved from each Skittle is the same, making each coloured water section the same density, which is why the colours dissolve at the same time, but stay separated unless you mix them together yourself.

How long does the Skittles rainbow last?

The rainbow takes up to 30 seconds to start appearing and spreading towards the centre of the plate. The time it takes to spread to the centre depends on what size plate you use, ours took about 2 minutes to fill the whole plate.

How to make a Skittles rainbow.


Disclosure - This post contains some affiliate links which means I may earn a small commission, at no cost to you, should you make a purchase. 

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