You will be able to see Datacrons from quite a distance as they emit a large glow around them and shoot a beam of light into the sky. If you are very close to a Datacron you will also be able to hear the sound from them.
Datacron Locations By Planet
Voss – 5 Datacrons
Red: Strength +4
Location: 651, 2049
To start head to coordinates 356, 1964 in The Gormak Lands. From there head east towards them mountain and follow the path to the left at the base of the mountain. Stay on the path all the way until you come out of the crevice. Once you are out in the open again, head to the rock formation on the left. The Datacron is sitting behind one of the large rocks.
Green: Endurance +4
Location: -1945, -2230
Head to the entrance of the Shrine of Healing in The Old Paths area (coordinates -1957, -1552). Head into the Shrine of Healing following the path straight back, down all of the stairs. In the large room at the bottom you will see the Datacron in the middle of the room. However you will not be able to pick it up yet. First head to the back right corner of the room. There you will see a Voss Mystic standing in front of a Healing Crystal. Click on the crystal to mediate. Once the meditation is complete head back to the Datacron. Now you can meditate in front of it and collect it!
Orange: Cunning +4
Location: 521, 189
To start heading to coordinates 474, 222 in The Nightmare Lands. Behind the destroyed walker is a Fallen Trooper. Loot the Fallen Trooper to receive the Shield Codes. Once you have the Shield Codes head over to the dais with the force field and interact with the Shielding Keyboard. This will deactivate the shield and start the elevator. Hop onto the elevator and take it to the bottom. There you will find your Datacron.
Purple: Willpower +4
Location: -29, 371
This Datacron is pretty easy to get. Head to coordinates -442, 402, near Fort Kodentha. From there you will see a grassy trail. Follow the trail until you reach the rock formation at coordinates -432, 179. Climb up the rock formation to the top. You will see a cave entrance there. Follow the cave to the end to collect your Datacron.
Yellow: Presence +4
Location: 2000, -940
Head to the northeast corner of the Nightmare Lands. You will find a small island that is occupied by three Voss Mystics. Near the meditating mystics you will see a Meditation Tablet. Click on the tablet, this will put you in a dream state. From there you can collect your Datacron.