It seems most of the places i went people asked about my yellow lightsaber. This was when i was only on coruscant, but still i searched the fourms and couldnt find a topic on this. So ill just explain now. To get a free Yellow color crystal(Solid yellow, not the yellow and black pre-order) you must
Go to tython
Go to the far left side of the jedi temple
There should be and old jedi talking to someone(will have the triangle over his head)
Talk to him, and he will tell you to go investigate his padwan, because he thinks he is in love with another padwan
Go to the area he tells you to, and talk to them. They tell you if you lie for them, they will give you a rare crystal
Go back to the master, You will get a lightside/darkside choice.
If you're willing to get a few darkside points, then lie.
After that report back to the padwan, and collect your reward.
Sorry if there is actully another topic on this, but thanks anyways