Color grading is an art form. It can change a movie experience, for better or worse. As with any great art form, good artists (i.e. colorist) are rare. Having the talent of understanding color grade and the psychological aspects is crucial. I find color grading fascinating but also very hard to comprehend. However, the blog Digital Cinema Foundry, has made a post on how color grading works. Read it her.
After color grade:
Stu Maschwitz has made a tutorial on how to you grade your material to look like a Hollywood blockbuster. With tools like Colorista and Color Looks, you are able to make quick color adjustments in order to get that blockbuster look. The Final Cut Pro standard 3-way color correction filter is also useful.