how to use -f[no-]color-diagnostics clang option with ports

[Anton Shterenlikht]

	From makc at freebsd.org Thu Feb 21 13:47:30 2013
	> clang colours corrupt script() output, e.g.:
	> 
	> #warning This file includes at least one deprecated or antiquated header. \
	> ^[[0;1;32m ^
	> ^[[0m1 warning generated.
	> ^[[31m^[[1mLinking CXX executable ../../../bin/pvbatch
	> ^[[0m[ 91%] Built target pvbatch-real
	> 
	> Can I use something like this
	> 
	>  CFLAGS+= -fno-color-diagnostics
	>  CXXFLAGS+= -fno-color-diagnostics
	> 
	> to suppress colour?

	CMAKE_ARGS+=	-DCMAKE_COLOR_MAKEFILE=off

I put this in /etc/make.conf:

# grep COLOR /etc/make.conf
CMAKE_ARGS+=    -DCMAKE_COLOR_MAKEFILE=off

but building e.g. science/paravew in script(1),
I still get corrupted output, e.g.

In file included from /usr/include/c++/4.2/backward/strstream:51:
^[[1m/usr/include/c++/4.2/backward/backward_warning.h:32:2: ^[[0m^[[0;1;35mwarni
ng: ^[[0m^[[1mThis file
      includes at least one deprecated or antiquated header. Please consider

Or is this nothing to do with colour?
Then how can I get rid of these special
characters?

Thanks

Anton