Colour Science Experiments for Preschoolers

A child's hands and arms are visible as they participate in a colorful art activity, dripping blue paint into a large black tub filled with oobleck and splashes of red, yellow, and blue. A wooden tray holds several small glass jars containing red, orange, yellow, green, blue, and purple STOCKMAR watercolour paints on a white table.

Art Meets Science: Easy Colour Experiments for Preschoolers

Welcome to the Oskar's Wooden Ark Colour Lab - where curiosity gets messy, colourful, and wonderfully scientific. 🌈

We're so excited to share two of our favourite hands-on experiments, brought to life by Jess - mum of four boys and Play Extraordinaire.

Whether you're looking for a rainy-day activity or simply want to spark a little wonder, these experiments are designed for little scientists who love to explore. The best part? Both use simple household ingredients you likely already have at home - and feature our beautiful STOCKMAR Aquarelle Watercolours to bring the colour magic to life. (Or if you don't have STOCKMAR Paints, try with food colouring!).

Experiment One: DIY Lava Lamps

There's something utterly mesmerising about watching coloured blobs rise and fall through oil - and this experiment delivers that wow factor every single time. Your little ones will explore what happens when coloured water and oil meet a surprise ingredient, creating their very own erupting lava lamp at home. It's quick to set up, simple to run, and guaranteed to have everyone gathered around the jar in wide-eyed wonder.

You will need:

Water
Vegetable oil
Alka-Seltzer tablets
STOCKMAR Aquarelle Watercolours

Step 1: Mix STOCKMAR Aquarelle Watercolours to create your desired colour in paint pots.

Step 2: Fill clear jars with ⅓ coloured water and ⅔ oil.

Step 3: Break the Alka-Seltzer tablets into pieces, drop them into the jar — and watch the eruption begin.

Watch the Tutorial

Experiment Two: Colourful Oobleck Art

Meet oobleck - one of the most fascinating textures in the world of sensory play. Pick it up and it feels solid; let it rest and it flows like a liquid. This strange, wonderful substance is made from just two ingredients - cornflour and water - and becomes an open canvas for colour exploration when paired with Stockmar Aquarelle Watercolours. It's science, art, and sensory play all rolled into one glorious, squishy experience. 🎨

You will need:

Stockmar Aquarelle Watercolours
A tray
Cornflour
Water
Droppers or pipettes (tip: old soy sauce fish packets work brilliantly)
Glass Jars with Wooden Paint Holder

Step 1: Mix 1 cup water to 2 cups cornflour to make your oobleck. Dilute Stockmar Aquarelle Watercolours with water using your Glass Jars with Wooden Paint Holder.

Step 2: Use pipettes or droppers to drip colour onto the oobleck surface.

Step 3: Use a skewer to swirl the colours into a beautiful marbled pattern.

Step 4: Add more Stockmar Aquarelle Watercolours to deepen the colour - try mixing blue and red to create purple.

Step 5: Let the oobleck dry for easier clean-up. Dried oobleck is surprisingly fun to play with too.

Watch the Tutorial

The Learning Behind the Play: STEM Through Colour

These experiments are so much more than a fun afternoon activity - they're quietly doing some serious work.

The Lava Lamp, explores concepts like density, buoyancy, and chemical reactions in a completely hands-on way.
Oobleck introduces the fascinating world of non-Newtonian fluids - materials that don't behave the way we'd expect - which is the kind of mind-expanding discovery that stays with little ones long after the mess is cleaned up.
Add colour mixing into both activities and you've woven in colour theory and creative expression alongside the science.

This is what STEM through play looks like - joyful, open-ended, and full of genuine discovery.

Ready to explore more STEM fun? Discover our thoughtfully curated STEM Through Play collection - filled with beautiful resources to nurture curious, creative thinkers at every stage.

STEM Through Play