Customize menu > Preferences > Preference Settings dialog > Gamma tab
On the Gamma panel of the Preference Settings dialog, you set options to adjust the Gamma values for input and output images and for the monitor display.
Interface
Enable Gamma Correction: Applies any gamma adjustments you make. Turn off to disable gamma correction.
Load Enable State with gmax Files: Loads the state of Enable Gamma Correction with each GMAX file.
When you choose Load Enable State, and load a GMAX file whose Enable Gamma Correction state differs from the current state, you can make the gamma correction correspond with the setting in the current file or leave the setting as is.
If you have a gmaxstart.gmax file and you choose this option, new sessions of gmax use the Enable Gamma Correction state in the gmaxstart.gmax file. If you turn this option, the gmaxstart.gmax file doesn't affect the state of Enable Gamma Correction.
Display group
You use display gamma for the color selector and color swatches. Take note of the default value before you start making adjustments in case you need to restore it.
Gamma: Adjusts the gamma display for gmax. The field increases or decreases the value (lightness or darkness) of the solid gray center square. Adjust the value until the center square is as close as possible in value to the surrounding checkered square.
If you're creating imagery that will be sent to someone, turn on the Gamma options to assure yourself that the image will look correct at the destination site.
You can also display these gamma settings from the Gamma button in the File Browser dialog.
Bitmap Files group
Input Gamma: The system input gamma that gmax uses to process bitmaps if that bitmap type doesn't override the gamma with its own gamma value. You use the Input Gamma to invert the gamma of bitmaps coming into gmax (for example, texture maps).
Tip: If you have gamma enabled when loading texture maps, set your input gamma to the same value as your display gamma, or your maps will be too bright.
Output Gamma: The system output gamma that gmax uses to process bitmaps if that bitmap type doesn't override the gamma with its own gamma value.