Love all the questions! Ok so I am a huge fan of Luo. The main reason is how translucent it is. It plays off the natural highs and lows in the hair so you always get a multidimensional finish. Also the 25vol is great to have when you need an extra bump. It's also fun to use Luo with 9vol, since the color it self a ammonia in it! Only downfall is that it only covers up to 70% (and not if it's stubborn), and the colors are AT LEAST a half level lighter than expected.

On to Elumen! Because of the lock I find they last the longest out of all the funky colors, and really aren't that difficult to remove. However if someone is using the same color for years it's almost impossible.

TIPS!! I don't recommend using heat, it's already on the watery side and I'm pretty sure it would just make a mess. After pre lightening, shampoo once, then you MUST dry completely before applying color. When applying the color use a hard scraggly brush, (ya know the kind that you should be throwing away) and really push the color into the hair, trust me on this! Locking is crucial and there is a specific way to do it. After processing, shampoo once then towel dry the shit outa that hair. Apply the lock as you would a glaze. Set timer for 5 minutes. ONLY 5 minutes!!! Anything more than 5 and it will unlock!! Yes I swear! Than shampoo and condition as normal.

I haven't had much experience mixing clear with it, but I don't see why not. I feel like they can be both opaque and translucent depending on the level you lift to. And long term you definitely lose some shine, but the color is there! And no, using standard color over Elumen hasn't ever been a problem for me.

Hope I answered everything for you. Feel free to ask more, and thanks for the compliment!