We’ve had science fun making this amazing colour-changing thermochromic slime using thermochromic dyes. This is a slime that changes colour as it uses a pigment sensitive to temperature, and here’s our quick guide on how we did it – very easy! Read on & watch the video too…..

You too can make colour-changing slime! Watch this….

If you have NEVER made slime before read this:

To make colour-changing thermochromic slime you need to know the basics of slime making, read this blog to help you get started with slime making.

If you have made slime before read this:

OK, so now you can confidently make slime you must have a go at this magical colour changing slime.


A bowl
A stirrer/spatula
Clear PVA glue
Your preferred Borax solution (we make up our own solution using 2.5% sodium tetraborate)
Thermochromic dye in powder form (various colours to choose from) see lab notes below
Gloves & goggles


First I protected the work surfaces!
I added a slosh of glue to the bowl and stirred a sprinkling of thermochromic powder in….. (do you like how science-based my descriptions are, this would never have made it to a lab report!)

I didn’t use much powder at all, about a quarter of a teaspoon. This dye took a while to blend in as it clumped together at first.
Once I was happy I’d mixed it in well enough, I started to add my borax solution a little at a time, until the slime started to form and pull away from the sides of the bowl.

This is when I know the slime is ready to be moulded, stretched and squished using my hands. This is the last stage of slime-making and although messy to start with, as the slime forms it comes off my hands and gets less sticky. If it doesn’t get less sticky and it still a mess all over my hands, I just squirt a bit of borax solution directly into my hands to fix this.

Make thermochromic slime – the video

lab notes

What is thermochromism?

Thermochromism is the property of certain substances to change colour when the temperature changes. A mood ring is a well known example of a temperature sensitive item. The dyes have been manufactured to change colour at a certain temperature, so for the colour changing slime we chose a dye that was sensitive to 27oC so that it would change as it warmed up in our hands. There are several useful applications for thermochromic dyes, such as thermometers and hot drink indicators. There’s the fun side too, as in jewellery, colour changing t-shirts and slime!

We bought our thermochromic dye from SFXC, you can read more about them here.

Want more slime recipes?

Check out our other How To blogs here:
Magnetic slime
Fluorescent/Hallowe’en slime
Fluffy slime


Good luck & happy sliming

If you tackle this activity at home you do so at your own risk. If you have as much fun as we did, feel free to share your pictures with us on Facebook.
Bye for now

Chief Scientist at Sciencedipity