Final answer:
The colors in a geologic map represent different geologic units and help differentiate between different types of rocks. Landforms can be observed through the lines and contacts in the map.
Step-by-step explanation:
The colors in a geologic map represent different geologic units, which are subdivided by time and rock types. For example, shades of yellow are often used for Quaternary units and blues for Paleozoic units.
The colors help geologists identify and differentiate between different types of rocks and formations. As for the landforms, they can be observed in the map through the lines and contacts that represent different rock types and their boundaries.