Well sunday there was a little confusion about power and colour crystals on guilchat.
Now i'm still not sure but as i see it, it works like this.
u need a crystal to make your lightsaber work the colour of the crystal becomes the colour of your LS.
Now in more advanced LS 2de-4de Generation u can add Clear (power)crystals and krayth pearls to add to the DMG.
The quality of a crystal is not be seen unless u give it to a jedi for "Focusing" and then it will reveal its self as either Poor, Fair, Good, Quality, Select, Premium and Flawless , there is no clear relevantace between the HP of the crystal and the quality after focusing a 1200 point one can be poor and a 800 can be premium.
And as i know it there hasn't been a flawless one any server yet.
Well hope it helps and again i could be wrong since i'm not a jedi but i believe this is how it works.