perf timechart: Improve the visual appearance of scheduler delays

[from KS feedback]

Currently, scheduler delays are shown in a mostly transparent,
light yellow color. This color is rather hard to see on several
screens, especially projectors.

This patch changes the color of the scheduler delays to be a
much more "hard" yellow that survived the kernel summit
projector.

Reported-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091020064731.20ae126a@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>