help for a natural shade

Hello, girls! I came here to ask for your help because, even after extensive research by myself, I cannot for the life of me understand colors and tones. I finally have virgin hair(except for a few ends which I will resolve with Efassor). My hair is between 5 and 6 and I'd say it's a little cool toned(in bright light it goes towards green rather than red). I really, really want pretty hair because this color is so...meh, but I do not have the money to go to a salon and I thought that I could make myself pretty without a s**tload of money.
I want to preserve my roots so when it grows it doesn't look bleah because who has the time to do roots every month? I will do a balayage-type ombré with the help of my BFF but I don't know what colors to use!!! The head that tickles my soul is Cara Delevigne's. I absolutely looove the ashy but golden color(I don't even understand what colors she uses) and I thought that here you are all experts in hair color so you'd be kind enough to land me a hand. I will post a few links so you know what I'm talking about exactly.
Because I live in a shitty country, I don't have access to all the dyes and wonders that you talk about here. I have access to: igora, koleston, majirel, inoa, blondme, dialight

PS: Sorry if I made writing mistakes, I haven't used English in a long long time, and I'm not a native speaker.