I service mine every 5000-7000kms with Motul 8100 full synth and new filter. The colour of the oil...well, can't really describe that one can ya all I can say is that it looks healthy, not VERY black at all. Still a good dark shade of golden brown verging strongly on black. Car has 149,000 on the clock, had leaks on rocker gaskets that were hardly bad (fixed now) but doesn't lose any oil at all.
Most I've gone between service was 9000kms, but as soon as it got around 5000 I was checking oil level and colour frequently. This service interval consisted of a few easy going highway runs between sydney and canberra though, with very little hard driving.