A different approach to color adjustment is to use the COLOR_TABLE facility to do all of your customizations. With this approach, you don't use the COLOR_MODEL setting at all. Instead, you map each foreground-background combination that you use to the desired new combination.
This is usually more work than using the COLOR_MODEL setting, because you must select each color combination individually. However, this approach is straightforward and gives you total control over the colors selected.
The ACUCOBOL-GT debugger uses this technique. When you enter the debugger screen, it saves the current color table and then creates a new one that maps the usual debugger colors to colors more appropriate for a graphical environment. When the debugger restores your application's screen, it also restores your color table.
COLOR_MODEL and COLOR_TABLE are described in the help. It's likely that you can achieve the effects you want with these two variables alone. If you discover that you need additional fine-tuning, see Additional Color Configuration Variables for more information.