This variable is typically used when a character-based application is moved to a graphical environment. It determines how the initial colors in an application are transformed. By default, it is set to "0", which causes no transformation. It may be set to any of these values:
1 This mode causes the foreground and background colors to be exchanged for each other. This is equivalent to running the entire program in reverse-video.
2 This causes white to be exchanged for black and black to be exchanged for white. The foreground and background colors are transformed independently. For example, a green foreground on a black background would turn into a green foreground on a white background. This setting usually has the effect of transforming a black background into white while maintaining the general color scheme of the application.
3 The foreground and background colors are exchanged for each other, but only if they are either black or white. If either the foreground or background contains a color other than black or white, then nothing happens. This is equivalent to running the monochrome parts of your program in reverse-video while maintaining the color portions unchanged.
4 The foreground and background colors are exchanged for each other, but only if the background is black. This mode ensures that you never have a black background.
5 If the colors are foreground white and background black, they are exchanged for each other. Otherwise, nothing happens.
Note that if your application is entirely black-and-white, then the first three COLOR_TRANS options are essentially identical.