Colour Theory with Squishy Bags

These squishy bags are a great, mess free way to experiment with mixing colours and colour theory. After we’d finished experimenting by making different colours we put a sheet of cardstock inside each paint filled bag, sealed the bag again and used them to practice forming letters and numbers with our fingers.

Here at Science Sparks, we’re trying to reduce the amount of plastic we use, so wash out the bags and save them for another activity once you’ve finished.

Colour Mixing Squishy Bags

Materials

Small sealable plastic sandwich bags

Red, yellow and blue washable paint

Small sheets of cardboard/stock

Instructions

Place two small blobs of different coloured paint into each bag.

Carefully seal the bag and gently squish the colours together until they mix. You should find:

Yellow + Blue = Green

Red + Yellow = Orange

Blue + Red = Purple

Once you’ve finished experimenting, place a small sheet of card inside each bag and carefully seal it up again.

Children can write letters and numbers on the bag’s surface, which can be wiped clean and used again.

Mixing colours – why does this work?

What are primary colours?

Red, Yellow and Blue

Primary colours cannot be created by mixing other colours.

Secondary colours are made by mixing primary colours.

Tertiary colours are made by mixing a primary colour with a secondary colour.

Always supervise small children when using paint and plastic bags

Last Updated on February 7, 2025 by Emma Vanstone