Final answer:
To make a darker shade of blue, mix blue paint with a small amount of black paint.
Step-by-step explanation:
To make a darker shade of blue than sky blue, you can mix blue paint with a small amount of black paint. The black paint will darken the blue and create a deeper shade. Start with a small amount of black paint and gradually add it to the blue paint, mixing thoroughly after each addition until you achieve the desired shade.