The filters in the Color Correction category can be used in a number of ways. For example, you can set a mood by making an image sepia-colored. In addition, these filters can fix a problem with contrast, color, gamma, or brightness.
There are 17 Color Correction filters:
Brightness boosts or lowers the uniform brightness of an image.
Channel Mixer allows cross-mixing of red, green, blue, and alpha channels into one another.
Color Balance adjusts the relative balance of all three color channels of an image, allowing two images to be color-matched, for example.
Color Reduce reduces the full range of color in an image to two, three, or four colors.
Colorize substitutes the blacks and whites in an image with colors you select.
Contrast adjusts the difference between the lightest and darkest parts of an image.
Gamma adjusts the relative distribution of brightness in the midtones of an image.
Gradient Colorize uses each pixel’s color value to determine the application of a color value from a gradient.
Hue/Saturation adjusts the hue, saturation, and value levels in an image.
Levels remaps the white and black points of an image.
Negative inverts color and brightness in an image.
OpenEXR Tone Map applies tone mapping to an OpenEXR image.
Sepia tints an image with a sepia tone.
Threshold reduces all colors in an image to a duotone.
Tint tints an image with a single color.
YIQ Adjust allows color adjustment in YIQ color space.
YUV Adjust allows color adjustment in YUV (Y’CBCR) color space.