You are in a very similar situation to me 
I am IRL mid/dark brown hair. I used a Superdrug dye every so often (when the greys got too much)
In my teens/twenties I was everything from short jet black to waist lemgth henna .
But since growing my hair from my short pregnancy hair (my DC are teens now) to a collarlength bob in brown, it was safe and boring.
I had a layered cut three years ago, hated it and had it cropped.
My new growth which I'd used a slightly lighter dye on, was gorgeous, chestnut brown.
So over the last year I've gone even lighter (I use a 10.0 or 10.01 at the moment) and like you I'm coppery.
I have put some highlights in time to time.
I have pale freckled skin and hazel brown eyes so I can go from black to light , it suits my colouring
My hair is short (about 2" on the crown) cut every 5-6 weeks dyed (by me) every 3 weeks.
I have been dithering about going back to my darker shade (the same colour as my pesky roots)
But I saw some photos of myself with dark hair and though OMG....No !
Your skin changes (I don't know how old you are but I'm 49, nearly 50). I would need to rethink alot of my clothes , make up, my attitude about myself. It took a long time to visualise myself as coppery (blonde bits if I highlight) now I don't think I could see myself dark again.
If you want different, why not go for the highlights next time? Be striking blonde for the summer.
You could use a wash in over the top (provided you don't go green. Or pink)
to make a change then if you don't like it , wash it out.
I have complete strangers saying "I like your hair"
Not "Hmm your hairs a nice colour what dye do you use"
Though I always say "Thank You, but it's not real " 