Pre-softening non grey virgin hair?

I can't see why it'll be any different. You're not leaving it on for long, so no need to put it on the lengths first.

I've pre-softened mine which has very minimal grey before using the same methods as people use on grey hair and I found the 10 vol didn't really do much so I moved up to 20 and that worked a bit better. No reason why you shouldn't start with 10 first though, your hair might be more receptive to it. It never really makes the colour take as well as it does over bleach or a permanent dye but it certainly helps.

(Oh and I can't really answer the question about the roots, sorry, as I only did my roots, my lengths were already dyed)

Thanks both 🙂

I'm wondering now if perhaps a box dye might be better for a base...does anyone have any idea what volume developer they use in the permanent red XXL dyes?

Pretty high. I don't know for sure, but I'm fairly certain it's a 30 vol. they always use higher than it really needs to guarantee results on everyone.

I tried to find out when I used to use Live XXL and the info doesn't seem to be anywhere, that's why I stopped using box dyes as like Janine says they need to make sure it takes even on dark hair so it seemed a waste to use something so strong when my hair doesn't really need it.
At the moment I use Wella Koleston in 5/4 (as I like a red or ginger tinge to it) with a 20 vol developer as my base to give depth to my colour, then I use various shades of adore to top it up and make it redder or browner depending on my mood. I also use Directions Alpine Green on one part of it, and it shows up pretty well over the brown dye.  (I think I will just pre-soften in that area in future though as it goes much more blue/teal over my natural colour with it being really ashy), it lasts way longer on the dyed bits though.
I did try a Castings semi permanent originally and the adore stuck quite well over that for a while, but then it eventually stopped doing, but I'm not sure if that was because my hair was bleached underneath.