We all spend a fair amount of time in our classes teaching and learning about the Color Wheel. Here are some great videos by The Floral Design Institue that might help with the understanding and visualization of color harmonies.
"An Introduction to Color Theory"
"A Study of Monochromatic Color Schemes"
"A Study of Analogous Color Schemes"
"A Study of Triadic Color Schemes"
"A Study of Complementary Color Schemes" (Including split-complementary)
"A Study of Polychromatic Color Schemes"