1) After messing up with some colors on torishop I've come to a conclusion that Demon is the best when it comes to force colors. It's just like Pure, it goes well with everything, and I don't like Void with other dark colors.
2) Welp, Demon for the reasons stated above.
3) Demon/Juryo, Demon/Dragon, Demon/Sapphire, Void/Blossom, Static/Both, Warrior/Demon.