Amazing, Heat-Sensitive Color Changing Slime Recipe for Kids

This amazing color changing slime is going to blow your mind! The easy-to-make heat sensitive slime will actually change color as your kids touch it because of the thermochromatic pigment you can easily buy on Amazon! This fun color changing slime recipe is a great science activity for preschool, pre-k, kindergarten, first grade, 2nd grade, 3rd grade, 4th grade, and up toexplore by playing. Let me show you how to make color changing slime with our thermochromic slime recipe that only takes 5 minutes! This is the best homemade slime recipe!

Color Changing Slime

I love kids activities that really WOW! You know the kind, where kids are impressed while they are completing the activity for kids, but also talk about it for days, weeks, and months afterwards. Those are my favorite things to try. I know we are not only having fun, but creating memories of epic childhood days playing and learning together with a science project for kids that will WOW! This color changing slime is definitely one of those cool projects for kids to try. It takes the fun of amazing, fun-to-play with slime up a notch… or two! They will have fun playing with this heat sensitive slime, watching the slime sheet, flow, ooze, and instantly come back together nice and neat. But thing amazing activity will actually change colors right before your kids very eyes!

And if you want to – you can even teach them about science in the process! Ready? All you need are a couple easy-to-get supplies and I will show you how to make heat sensitive slime. This science activity is loads of fun for preschoolers, kindergartners, grade 1, grade 2, grade 3, grade 4, grade 5, and grade 6 students.

Heat Sensitive Slime

This has to be one of the coolest play recipes ever! All you need is 5 ingredients and 5 minutes and you get to play with this color changing, heat sensitive SLIME! Kids of all ages – from toddler, preschool, pre k, kindergarten, first grade, 2nd grade, 3rd grade and more – will have fun exploring scientific principles of trial and error as they make cool patterns and changes in the color of the thermochromic slime.

If you want to try our favorite “regular” slime – don’t miss our favorite 2 ingredient Slime or our dish soap slime.

Before you start, you need to decide what your color scheme will be for the slime. It will start out one color based on the thermochromic pigment you use (when the dough is cold), and change to an alternating color based on the food coloring you used (hot color).  You wan to think color wheels when picking your colors as you will see variations of the colors as the hot and cold colors mix….Think color wheel neighbors to make the transition smooth.  I used:

• Blue pigment with yellow food coloring (Slime is teal and turns yellow when hot)
• Red pigment with yellow food coloring (Slime is orangey red and turns yellow when hot)
• Blue pigment with red food coloring (slime is purple and turns pink when hot)

Color changing slime recipe

To make this THERMOCHROMIC Slime all you need are a few simple materials you can order on Amazon or pick up at your local Walmart.

• 1/4 cup white school glue
• 1 Tablespoons water
• 3 teaspoons Thermochromic pigment
• 1/4 cup liquid starch 
• Food coloring

How to Make Color Changing Slime

Okay, to make this color change slime, start by pouring 1/4 cup glue into a large bowl.  Add 1 tablespoon water and stir until combined.  Add 5 drop of food coloring (see above for ideas) and mix well.

Thermochromic slime

Then add 3 teaspoons of thermochromic pigment and mix until uniformly distributed.

Colour Changing Slime

Now add in 1/8 cup liquid starch (StaFlo) and mix until thick and slimy.  Then knead the slime with your hands and return to the starch mixture for another mixing.  This step is important because it makes sure there’s no unmixed glue hiding in the center of your slime ball.

If slime is still sticky, add additional starch a little at a time. Make sure to knead until it is no longer sticky.  Most batches will use the entire 1/4 cup sta flo that is indicated in our slime recipe above.

How to make heat sensitive slime

Store heat sensitive color changing slime in a glass or plastic container with a lid for up to one week.  If you haven’t played with it for a couple of days you might need to add a little additional starch to it, one teaspoon at a time.

Want to see what this AMAZING color changing slime recipe looks like in action as your kids play? Keep scrolling….

Thermal slime

Just like “traditional” slime, this slime is fun to knead, squish, watch pour into a pile and pick back up easily to play some more.

Homemade Slime

But unlike regular slime, this fun slime recipe will change colors as your child plays. The pigment reacts to heat. When the dough is cold it will be the color of the thermochromic pigment you used. But when your child touches it it will change to the color of the food coloring. Amazing right!

How to make butter slime

We taught you how to make color changing slime, but are you curious as to why it works?

This slime gets its color changing super powers from thermochromics pigment. As the temperature changes, Thermochromic materials change colors. You’ve probably seen this reaction before in mood rings, lipstick, and rubber duckies that tell you when the bath is too hot for babies.

There are two main types of thermochromics materials

1. Liquid crystals – temperature changes cause the crystals to move, changing the spacing between them. This causes light to refract at different wavelengths, creating different visible colors.
2. Leuco dyes – instead of changing the distance between crystals, temperature changes cause the dyes to change molecular structures. One form reflects colored light, the other colorless.

Slime recipe without borax

For older students, use this activity to get them thinking. Ask them questions like:

• Why do you think heat changes the slime?
• What happened when you touched the slime?
• Where have you seen other items that are heat sensitive?

Easy slime

Go a step further as you as children to come up with a couple experiments using the slime. Have them use the scientific method: ask a question, gather information and observe (research), make a hypothesis (guess the answer), experiment & test your hypothesis, analyze your test results, and present a conclusion.

• What will happen if we put an ice pack on the slime?
• What happens if we use a hair dryer to heat up the slime?
• If we let the slime dry out will it still change colors with temperature fluctuations?

Making slime with glue

Whether you are a parent, teacher, grandparent, homeschooler, or organizing a day camp / science camp – you will love this outrageously fun & easy to try activity for kids.  The color and exploration possibilities are truly endless!