If you drive with full attention, you would notice white and yellow lines on roads. Difference of color and marking isn't because they were short of white paint to so they painted it yellow, rather there is message behind those yellow, white, solid and broken road lines. These lines are part of road signs, and need to be followed for road safety.
Solid White LineIt means that you must not change lanes while you drive, and should stay in the lane you are already on.
Broken White LineIt means that you are allowed to change lane, but safely and when it is needed.
One Solid Yellow LineIt means that overtaking is allowed if there is enough space, but you can not cross the yellow line.
Double Solid Yellow LinesIt means passing or overtaking is not allowed, and you must remain in your lane.
Broken Yellow LineIt means that passing or overtaking is allowed over broken yellow line, but with caution.
Solid Yellow Line with Broken Yellow LineIt means that if you are driving on the side of the broken line, you're allowed to overtake, and if you're driving on the side of the solid line, you're not.