Disclosed is an apparatus for assisting a vehicle, including: a gear mounted in a vehicle and configured to switch an operation mode into any one of a travelling mode, a parking mode, a neutral mode, and a reverse mode of the vehicle; one or more lighting devices provided in the vehicle; a camera mounted in the vehicle, and configured to obtain an image around the vehicle; a processor configured to decrease a gain of a first color in an RGB image, which is received from the camera and includes light emitted from the taillight when the operation mode is switched into the reverse mode; and an output unit configured to output the image processed by the processor.