I googled about it, but I still don't know how to get those items.
Hello,
There are few ways to get them.
1. Buy them from other players.
Its easy way but is expensive. Sunny jade 20-25 g/each,Green jade 1000 g/each,Twilight 35,000-50,000 g/each, Red jade don't know the exact price.
2. Torment Tower Instance.
After finishing the instance you get a box that give you sunny and green jade's, there is chance to receive twilight,red jade's.
3. The Mortal Trial.
Its special place where you can grind monsters and farm them, you can enter there via Imperial Citadel npc-Lonzan in Sunstream,it will cost you 500gold to enter.
Thanks for the very useful answer!