When most people think of color correcting they think of giving their film a "look". Yet, there's more to color correcting than just giving your footage a "look". Color correcting, when done correctly, should help tell the story you are trying to convey. That could be through a "look" as if you're in the desert or a battlefield but mainly it's used to help focus the viewer's attention to the main subject of the scene.
Take a look at the two images below. The image on the left is the original camera footage. Your eye is immediately drawn to the traffic on the road as that's exposed properly. The driver (who is the main character of the film) is in silhouette. By applying simple color correction to the shot and reducing the exposure of the oncoming traffic and increasing the exposure of the driver your attention is now drawn to the film's main character. This simple use of color correction helps draw the viewer's attention into the story and focuses them on what's important - the driver getting bad news.
In the next scene, the main character enters a bar to drown his sorrows and meets a mysterious woman. You know they are in the same bar as they begin a conversation; yet, things just don't feel right. The woman is over exposed while the man is underexposed. You're mind starts to wonder if they are in the same bar.
Color correcting helps this by balancing out the exposure of both shots. While not perfect, the balanced shots make it more believable.
Problems always arise while on a film set. Whether it be footage shot from two different cameras, time of day, lighting setups, etc. Simple basic color correction techniques can overcome those problems and help focus your viewer's attention on what is important in the frame as they tell their story.