Screen color

The color of the screen is by default black and white. Depending on the computer it may be white characters on a black background, or black characters on a white background (if the main colors of your screen happen to be black and white). The command line is represented in the inverse colors. The simplest color control is with the Alt-C command. It exchanges the color attributes of the message line and the text screen. This is remembered as a `toggle' command. It is written in the default file with the DW command (p. [*]) and upon startup stedi sees whether it should flip the color of the screen. On some systems it is possible to ask for the color of the screen, in which case an attempt is made to fix this color exchange in an absolute sense. On other systems this parameter doesn't involve an absolute color.

For some color systems there is a more flexible way of controlling the color. The commands

    c1 color1 color2
    c2 color1 color2
sets the colors for the text screen (c1) and the message line (c2) respectively. The first color is the foreground color i.e., the color of the characters, while the second color is the color of the background. On the computers in the PC family the foreground color can be a number in the range of 0 to 15 (4 bits in total) while the background color can be a number in the range of 0 to 7 (three bits). The meaning of the bits in these numbers are:
bit 0
If set the color blue is on.
bit 1
If set the color green is on.
bit 2
If set the color red is on.
bit 3
If set the high intensity attribute is on.
So the commands
    c1 7 0
    c2 1 7
sets the text screen to white characters on a black background and the message screen has blue characters on a white background.

All the above variables are stored in the default file when it is written.