I've put together a small explanation of how the vBulletin Rep System works
from what I had gathered on the Web..
I submitted it to the admin before posting it on LPF...
Basically the dark bars are Reps from members with no or negative reps and
can not increase your Rep count.
The green bars are Reps from members with reps points and they can increase
your Rep count.
Your total number of valid reps is shown at the bottom of your profile rep page.
The Rep Power points is another thing... and does not follow the Rep points..