Please share your experiences with demi colors

Hi all,

I have been reading on this forum for a few months, I'm happy I found this place :)

I color my own hair with some help. My natural is a level 7 with strong gold tones. I lift the roots every 2 months with a neutralizing highlift, and then deposit a darker cool tone on top - in order to achieve cool saturation.

I ordered shades eq and waiting for it to arrive - my first experience with this color.

I would love to hear some feedback from anyone who used goldwell colorance demi, or matrix color sync : do the 6-7 level (cool - blue / violet) colors have some brown background in them, or are they a pure tone ? (I don't want to deposit any type of brown or warm tones). Has anyone tried to use colorance demi or matrix color sync over highlighted hair or for a tint-back ?

What were your results ? how long did the color last and what is your opinion of it ?

Any info would be greatly appreciated !