The image that a filmmaker wants to transfer from their head to the screen has to go through more than just storyboarding and filming. After the images are captured on film, they have to be adjusted to account for film quality, lighting issues, and unexpected problems. One of the most common, and in fact, required, steps in post-production is to correct and grade the color of the film. But if the color is already being corrected, why do you need the extra grading right after?
Look vs. Mood
You can look at color correction and grading this way: correction is about the look, while grading is about the mood. Color correction is the correction of the color in the film. If the film turns out to be too light or washed out, color correction remedies those problems. Grading, however, adds a mood to the film that correction can't provide. While you could definitely add the colors you want during correction, you might not end up with the same effect that you would had you gone through the actual grading step. Trying to go from uncorrected film to a properly graded mood doesn't work as well because you're not dealing with images that look normal to begin with.
Mood Affects Sound
When you adjust the sound in post-production or try to add a soundtrack, you need to know what the mood of the film will be. The visuals are the best way to convey that mood, meaning that grading has to be done early on in the process. If you try to add music to film that's color-corrected only, the music may not convey the right tone. And if you try to add color grading after adding the music, then the entire film could turn out much different from what you imagined.
Dedicated Software Offers the Most Options
You can do color grading with a range of tools, including plugins, but software that was created specifically to handle correction and grading is the best option. Intuitive interfaces and fast response make the filmmaking process go a lot more smoothly, and you don't have to worry about compatibility with other software like you would with a plugin.
As you evaluate your choices of software, look for real-time previews and side-by-side views for better shot matching, and filters that help spot over undersaturated parts of the film. The more options you have, the more precisely your final film will match what's been in your head all this time.
Contact a color grading software company like Cinema Grade to learn more.