I love adding colour to water play by using food colouring. It adds another dimension to the sensory play, and it's great for mini lessons on colour mixing. Caleb decided he wanted to make green water, so I encouraged him to add yellow food colouring to the water.
He then added some blue food colouring...
...and was amazed as he mixed the colours and they turned green!
Although I have brought in some of our outdoor water table toys, I added in every day tools from around the house like spoons, cups, and funnels. This was a great way to introduce new vocabulary by naming the tools (e.g., graduated cylinder, funnel) and engaging in a discussion about how they might be used.