descending deeper into purple oblivion

so I've wanted pastel hair for years but never somehow got around to it?? i'm usually in the light platinum blonde - light cool brown range, now have had dark blonde hair for about three months. I was kinda going for my natural hair color but it felt so boringggg... so, a month or so ago I found a box of l'oreal preference ultra lightening whatever permanent dye in my drawer and cuz I was pretty bored i decided to slap it on (im not a good hair role model. i just dye it whenever im bored) and wow??? it turned out really, really silvery blonde? it's the color i'd been trying to maintain for ages and had already kinda given up on (silver shampoos never really do anything for me!!)

silvery goodness!!

inspired by my new fab ashy hair i finally got the courage to go pastel. i wanted a cool silvery-lavendery shade, so i got me some Directions - lilac, silver and plum, to be exact.
mixed lots of lilac, some silver and a dab of plum with a copious amount of conditioner. the result it yielded was pretty darn cute!!

also matching nails, rock on

but as excepted, that faded out in like two washes. so i went a bit darker.

like, every weekend when i retouched it my mix ratios were getting more and more color heavy. more plum, some silver to give it a cooler hue, and every time a little less conditioner.

then i gave up and just slapped undiluted plum/silver mix on my hair, and boy, pastels are cute and all, but this is srsly what i'm all about...

i'm letting this brilliant color stay as long as i still have dyes! any ideas on what to do next? :>