On the part that attaches to the battery? Blue is good! It's ready.
Uncharged is red, then it goes
through alternating red and blue, then solid blue is ready.
On the actual battery cable, most companies use blue or green for fully charged, though some just use red for uncharged and unlit for charged. For 2-piece chargers, the light on the AC to USB is irrelevant and just means it has power.
Here's a user guide
http://www.e-cigarette-forum.com/forum/vapor4life/58027-vaporking-user-guide.html
And a useful video - it shows both filling a blank carto (similar to adding juice to a prefiled one - just add less juice). With the current soft-caps, an unbent small paperclip is enough to remove the cap - stick it in the mouth hole just enough to pop out the cap. I usually hold a tissue on the threaded end and rotate the carto a bit when adding juice because the stuffing is a bit tighter these days and it's hard to add all in one place. When done, I dry the threaded end if needed, puff into the threaded end with the open end tilted down into the tissue to clear any juice from the air channel, and if any juice is pooled above the stuffing I may clean that up with a bit of tissue.
The channel-straightening part he shows is only for if you can't see light through the carto. I rarely need to do that but sometimes the channel will shift after using a carto for several days, and straightening the channel can improve a tight drag.
http://www.youtube.com/watch?v=8pyzOGQ0tMo
BTW it's PV - personal (or portable?) vaporizer