If you're using it in a RAID5 or similar configuration (eg redundant ZFS), Red is the way to go. Otherwise, go for Black.
The reason is simply that Reds are programmed to try for a very short amount of time to recover data which cannot be read in the usual way. This is very important because if the drive continues to try for more than a short amount of time to recover data, the RAID controller (whether hardware or software e.g. mdadm in linux) will mark the drive as bad and drop it from the RAID array.
Accordingly, it's better to go for Black if you're not using a RAID5 configuration as the drive will try for longer to recover any data which can't be read in the usual way, which is probably what you'd want in a non-RAID5 setup.