Colors are powerful tools for engaging children, from the youngest years onward. We hang brightly patterned mobiles above their cribs and help them learn the names of colors as they begin to record their own ideas in pictures and words. Colors can also open the door to an invisible world of electromagnetism, even when children can barely imagine things they cannot see. Colors aren't categories; they are part of a continuous range of electromagnetic energy ranging from the longest wavelengths (radio waves) to the smallest microwaves. If young scientists understand that there is an endless range of possibilities between, above, and below the colors they see, it will be easier for them to imagine the two-meter radio waves that open their car doors or the billionth-of-a-meter x-rays that can be used to image molecules like DNA. This article provides an activity sheet using plant pigments to compare plant pigments, and further explore color.