Red Soulstone

[Tracina]

I've gotten a few of the Blue Soul stones, but I have the option to select a red soul stone as a Veteran Reward.  A search on the forums didn't provide any insight.  Is it something different than the Blue soul stone, or is it different in color only?

[Amairgen]

The Veteran Reward Soul Stone has unlimited uses unlike the ones from Quests which can only be used 3 times.