Coloring help! (Root-ombre technique and opening pores)

Hey y'all.

I'm new here, but have been dying my hair for ~11 years now.

I'm just looking for any tips on two things:

--- The last time I dyed my hair, I tried bleach bathing- did it wrong by applying like I would shampoo (first on roots than ends). Dyed over with Adore's Chocolate Brown mixed with a mixture of Adore and Ion Brights purple shades. Faded horribly. Currently, my hair has ~3 inches of medium brown root regrowth, 4-5 inches of pinky-purple and 5-6 inches of varying shades of purple that I LOVE.

I'm hoping to get tips on how to cover up the pink-purple and my roots with more of the brown-purple mixture. I want to make it somewhat of an ombre/dipdye but... backwards. I don't want to touch my ends.

--- I don't want to bleach my hair, but I'm using semi-permanent colors, so I'm also looking for tips on ways to open the pores on my hair without really lightening my hair. I know dandruff shampoo/dawn can work some but was thinking maybe a very mild bleach bath with minimal time left on the hair might work as well. If anyone's tried something like that, I'd be very appreciative to hearing about the experience. Other suggestions are welcome as well.

Thank you!