Remember your Color Theory Exercise where we made a color wheel in Photoshop. Illustrator allows us to expand on this knowledge with some help using the Color Guides Panel. In it, you have access to many different color harmonies based on the color of your choice.
If you want to explore even more options you can click on the pie shaped wheel at the bottom of this menu which takes you to the EDIT COLORS menu. In this menu you can adjust and save your own color combinations based on color theories you have learned. (analogous, complimentary, triadic, etc.)
Draw and experiment with Isometric drawing. Remember to turn on Smart Guides and Preferences set to Construction Guides with 30 degrees.
Experiment using Color Guides Panel. Choose a fill color you like and scroll through color harmonies you prefer. Pick and fill other colors in harmony.
Make screenshots of Color guide choices. Screenshot is CMD+SHIFT+4. Draw a box around what you want to capture.