Guild Wars 2

Looking at the hero panel and see that for the stats there are two numbers, one in green one in white. why exactly are there two?

If you are in an area that is below your level, you will be down leveled so that you are more inline with a level appropriate for that area. That means, at lvl 80, if you are in the asuran starting area, you will be downleveled to around level 4 or 5 in some instances. The white numbers are you actual stats, the green numbers are your down leveled stats.

Hope that makes sense

The green numbers are also used to reflect any buffs that affect your stats. For example, a Warrior using Signet of Power will have a green number next to their white Power stat, showing the increase caused by the buff.