perf top tui: Give color hints just on the percentage, like on --stdio

And like it was in the old top.

Another change so that the familiarity with the old visual is maintained.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ypmyx9p0ah4byqaygrnb09x8@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>