You would be incorrect. I compared both in game and photoshop and they are identifical. Also, if you do a color match in-game, you'd see no change between any pieces. I think you are confusing this with the lighter green sets such as the electrum onslaught set.
Correct. The cartel has the Powered Assault and Tech armor and Electrum Onslaught is actually a match for the Phalanx set. Powered Assault is much darker and the helmet's camo scheme might actually look different with color matching than any of the others (never tried it tbh, but I've had issues with other sets.) You can find a similar set doing heroics from Voss and Corellia iirc. Vanguards can get a white or silver set, while commandos can get a camo green one. Ultimate Quadranium or something to that effect.
I have two pieces sitting in my bank but never bothered to get the rest.
As for me, I finally finished off another camo set with the Master Striker/Havoc look that I'm pretty happy with and get a ton of comments on.