A first basic step to understanding how watercolours ‘work’ is the use of washes in successive layers, these layers strengthen and deepen colour and tones. Overlaying different colours will also produce a ‘new’ colour tone.
Here is a simple experiment to help explain the practicalities, it’ll take you around 30 minutes, BUT you will need to let each layer of watercolour dry before adding the next layer… Enjoy!
Draw a design of shapes.
I’ve played with overlapping free hand drawn triangles.
Next mix a good amount of one colour in clear water, I used ultramarine.
With a clean brush load up with this wash and paint in the shapes aim to keep the edges crisp. I usually start at the edges and work into the middle, take care not to let your paint dry or you will get a stripey finish.
Notice how the overlapping layers of paint create darker tones.
Now try try adding a different colour, mix a wash using a clean brush and clean water!
I used ochre and drew a vertical stripe.
Then I mixed a wash of ultramarine and ochre and painted another vertical stripe.