This patch has one flaw with $C_H2 (patch is available in a mail sent by me a while ago). This one does not look very nice with a white xfce4 terminal and gnome-terminal (with Linux colors). It's cyan. For testing, I have a white xfce4 terminal with linux colors. The attachment shows how cyan looks on a terminal like this. Other colors seem to be fine.
Maybe a test with konsole and its exotic coloring may be useful.
Konsole's white and black color schemes are exactly the same as gnome-terminal's linux console colors and xfce4 terminal's default ones. Flaws described above.