The red marks are to starboard and the green to port, when headed south. The yellow marks help to prevent confusion when another channel coincides with the Waterway channel. For example, the upper reaches of the Pungo River have red marks to port and green to starboard when you are heading south. There are several places on the ICW where the navigation marks of a river reverse the normal color scheme you expect. Note these areas on the charts before they cause confusion.
Ranges are unfamiliar to many boaters, but they are frequent on the Waterway.
Usually, the front mark in a range will be below the rear mark when the two are in alignment. Ranges often have a vertical orange stripe to aid in daytime identification. When the front and back marks are aligned, the orange stripes are aligned. Most ranges are lit at night, and the daymarks are fluorescent. An example of a range is found in the mouth of Adams Creek, just after Mile 185.