Voss Datacron Locations

Flyroute from Voss-Ka to Fort Kodentha 
Color Purple
Stat Boost +4 Willpower
Codex Entry Galactic History #77: A Return to the Unknown Regions
Map Coordinates -650, 321
Details This datacron can be spotted while on the flyroute from Voss-Ka to Fort Kodentha. Go to -650, 321, heading east there is a path leading up the mountains, once up the path there will be a rock ledge with a gap.  Go in the gap and continue up the mountain and eventually you will bump into a bunch of rocks on which you can jump your way up to the tunnel, go through the tunnel (it's deserted so don't worry about enemy's), once out of the tunnel you should immediately spot the Datacron, it is on a circular display surrounded by pillars (a la Stone-Henge).   

Shrine of Healing 
Color Green
Stat Boost +4 Endurance
Codex Entry Galactic History #73: The Battle of Malachor Five
Map Coordinates -1910, -2305 
Details Inside the Shrine of Healing lower level -1950,-2230 
When clicking tells you, you need to be worthy. First, you must complete the Trials quest, which you get after destroying the Gormak AA.
After finishing the Trial (the last door might be glitched, it doesn't glow but you still click it to open it) in the north-east corner of the room you are in, there is a healing crystal-1910,-2305.
Activate it then wait for the meditation cycle to end. Afterwards you can claim the Datacron.  

Nightmare Lands (Spirit World) 
Color Yellow
Stat Boost +4 Presence
Codex Entry Galactic History #75: The Jedi Civil War 
Map Coordinates 2144, -42 
Details Northeast in the Nightmare Lands there is a small oblong lake with an island in it. On the island are 3 mystics chanting at a stone tablet at 2005,-953.
Activating the tablet will put you in a dream state and place you inside a cave with mystics and a Datacron. Claim the Datacron and return through a 2nd stone tablet. 

The Nightmare Lands (The Boneyard) 
Color Orange
Stat Boost +4 Cunning
Codex Entry Galactic History #74: Revan and Malak Fall 
Map Coordinates 515, 104 
Details In the back of the boneyard is a shield covered silo (same coords as the Datacron).
To open deactivate the shields, you need to find the fallen troopers body (443, 140), just east of the silo, behind the fallen troop clawler, which has the shield code on it.
Once you have the codes, there is a panel on one of the two smaller crate-like things next to the silo. Use it and it will deactivate the shields and activate the elevator.
The elevator will bring you down to the Datacron. (There is a panal next to the Datacron, in case the shield reactivates)