Pavement Markings and Object Markers
Pavement markings are the signs you drive on, and Colorado's exam asks you to read line color, line pattern and object markers correctly, especially where passing is and is not allowed on two-lane mountain roads.
Line color and pattern
Yellow lines separate traffic moving in opposite directions; white lines separate traffic moving the same way or mark the right edge. A broken line may be crossed when safe. A solid line should not be crossed. Double yellow with both lines solid means no passing in either direction; one solid and one broken means passing is allowed only for traffic on the side of the broken line. On divided highways the left edge is marked in yellow and the right edge in white.
Special lane markings
Two-way left-turn lanes are bounded by solid yellow on the outside and broken yellow inside, and are for turning only - not for travel or passing. White dashes or dots in an otherwise solid line extension mark exit and entrance gores. Wide white stop bars sit before signals and stop signs, and crosswalk markings define pedestrian space. Hatched areas bounded by solid lines are neutral and must not be driven on.
Object markers and raised markers
Object markers identify obstructions. Type 1 is a vertical rectangle with yellow-and-black diagonal stripes, Type 2 is a horizontal rectangle used on low objects, and Type 3 is a wide vertical marker for large obstructions. Raised pavement markers reflect white, yellow or red; red markers facing you in your lane mean you are going the wrong way.
Worked example
On a two-lane Colorado pass road you see a double yellow centerline with the solid line on your side and the broken line on the other. Passing is legal only for the opposing direction, so you may not pass. A passing zone that appears a quarter mile ahead does not change that until your side of the line becomes broken.
Traps
Reading a solid line as "never cross" instead of "do not cross except for a turn, driveway or emergency". Using a two-way left-turn lane to pass. Assuming yellow edge lines mark the right edge. Ignoring red raised markers as decoration.