Turning off color in clang error mesages?

Is it possible to turn off the colorizing of clang error messages? The
reason I ask is that using clang in an XEmacs buffer results in user
unfriendly output like this:

$ clang -c -Wall -Wno-switch -Wundef -Wsign-compare -Wno-char-subscripts
-Wpacked -Wshadow -Wmissing-declarations -Wmissing-prototypes
-Wstrict-prototypes -Wdeclaration-after-statement -Wunused-parameter
-ggdb -march=native -mtune=native -Demacs -I.
-I/usr/local/src/xemacs-beta/src -DHAVE_CONFIG_H
-I/usr/include/freetype2 doprnt.c
[1mdoprnt.c:127:7: [0m [0;1;35mwarning: [0m [1mexpression result
unused [-Wunused-value]
[0m Lstream_putc (lstr, zero_flag ? '0' : ' ');
[0;1;32m ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[0mIn file included from doprnt.c:34:
./lstream.h:332:34: note: instantiated from:
    Lstream_flush_out (stream) : 0))
[0;1;32m ^
[0m [1mdoprnt.c:136:7: [0m [0;1;35mwarning: [0m [1mexpression result
unused [-Wunused-value]
[0m Lstream_putc (lstr, zero_flag ? '0' : ' ');
[0;1;32m ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[0mIn file included from doprnt.c:34:
./lstream.h:332:34: note: instantiated from:
    Lstream_flush_out (stream) : 0))
[0;1;32m ^
[0m2 diagnostics generated.

If the answer is "no", then perhaps someone could point me to the place
in the code that writes out error messages, and I'll try and hack XEmacs
support in.

Thanks.

--- Vladimir

Is it possible to turn off the colorizing of clang error messages? The
reason I ask is that using clang in an XEmacs buffer results in user
unfriendly output like this:

It is -fno-color-diagnostics.

-Chris