System property to let end users set color scheme

[remkop]

TODO:

• test
• update manual

[remkop]

The below code snippet shows how a color scheme can be used to configure the usage help message style:

// see also CommandLine.Help.defaultColorScheme()
ColorScheme colorScheme = new ColorScheme()
        .commands    (Style.bold, Style.underline)    // combine multiple styles
        .options     (Style.fg_yellow)                // yellow foreground color
        .parameters  (Style.fg_yellow)
        .optionParams(Style.italic);

CommandLine.usage(annotatedObject, System.out, colorScheme);
...

==== End User Overrides

The following system properties override the color scheme styles. This allows end users to adjust for their individual terminal color setup.

.System Properties to Override the Color Scheme

picocli.color.commands
picocli.color.options
picocli.color.parameters
picocli.color.optionParams

For example:

java -Dpicocli.color.options=blink,blue -Dpicocli.color.parameters=reverse -cp app.jar com.app.Main

System property values may specify multiple comma separated styles.