perf ui browser: Honour the xterm colors

perf ui browser: Honour the xterm colors

So slang after all _has_ a 'default' color, call me color blind. Change
the default to it.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Link: http://lkml.kernel.org/n/tip-1dfxivxv0jhwldpds3v4zla2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>