What is tsch?
Do you mean tcsh? The shell? Colors are pretty independent of the shell you use. You probably mean: Can you have 256 colors at the command line?
That depends on your terminal emulator. The standard ANSI codes (standardized I think by ECMA) only standardize 8 colors, of which two (black and white) are of doubtful use (their exact definition depends on whether the emulator implements "black" as meaning "no light comes out" or "foreground color", and the definition of "white" is often actually "grey"). You can pretty safely assume that all modern terminal emulators running on color hardware have these 8 colors. For both the Linux and the FreeBSD console, it stops pretty much at this; I have tried sending the 256-color escape sequences to a Linux console, and it does NOT work. I vaguely remember hearing that one of the FreeBSD consoles has support for a few more colors (16? 80?), but not the 256 set.
For the original xterm (originally from the 1980s), there is 88- and 256-color support compiled in, and I've seen that work in most native GUI-based emulators, such as the ones that come with Gnome and KDE. I know iTerm2 (on the Mac) and PuTTY (on Windows) have 256-color modes. So all you need to do is: go find the document "xterm control sequences" on the web, read and understand it, and issue strings such as this to your terminal:
echo ^[ [ 31 m Hallo red ^[[ 38 \; 255 \; 0 \; 255 m Hallo purple ^[[ 0 m Back to black
(I added spaces for readability, quoted the semicolons, and printed the escape the way it looks on input).
Now all you need is to teach your applications to output these kinds of strings. Usually, the easiest way to do this is to set your terminal type to xterm-256colors, and it might start to work in applications such as emacs or vim.
