Next Hair Colour?

It's that time again, where I'm pondering a new hair colour! I wanted to keep the lilac a little longer, because I simply love the colour, however I hate that it doesn't cover the newly bleached hair. After a week or so, it's lilac with a considerable amount of dirty greenish yellow and even immediately after application you can notice some yellowish bits! It would mean double-bleaching the regrowth each time and I don't want to go down that road. I think as much as I love pastel hair colours, they are not for me because you need to be prepared for recolouring every couple of weeks and/or putting up with sections that don't take or using the colours as an extremely temporary measure. I'm too fussy for that!

I was going to do a poll, but have decided to leave it open to your suggestions. I don't necessarily want to go straight back to turquoise (although I loved it)-I'd like to try something new. I won't go bright pink again because my parents will shoot me (stained bath and all that). Here's a selection of what I've had over the past couple of years (above) and some pics that have been inspiring me below. I'm thinking perhaps a deeper purple? Or I still have lots of lilac left, so could mix a dark purple with that to hopefully get more coverage but not go too dark over the summer months? In the nicest possible way, I don't want it to look too 'standard purple' if you know what I mean? LOTS of people have dyed purple hair and I don't want it to look too 'dirty-grunge' because that's not me. I'm liking the newest colour on Katy Perry though, she's managed to keep it girly looking, but would I suit it? I also found an amazing super-bright purple on someone in a lookbook on a boutique/website and can't for the life of me find the image again, it was an intense but bright shade, it looked fab. I had a quick look for dyes online yesterday but got frustrated as everything I looked at was out of stock! Manic Panic have withdrawn some colours from sale for now, so you can't get them anywhere which is rather annoying. I loved the look of the new shades of Crazy Color (Bubblegum, Candy Floss and Marshmallow), but I've heard coverage isn't good nor long-lasting, which is a pity as they are super-pretty. So any ideas?