In Photoshop there are some option which options can helps to modify the color .Color Correction is the method of predominantly the adjustment of varying colors in your specific object. This process helps to adjust the contrast in your photos and also adjust color hue of the photos.To re- edit a picture it also supports the fine tuning brightness or darkness existing picture.
In easy words we can say , color correction is a process where you can choose specific color and adjust luminance level for your subject. of course you can change it anytime you like but you want to keep it the way you like your picture . Some one may be choose other colors . So it varies person to person.