What's the Name of That Book??? discussion

I read this book about 5 years ago but I'm pretty sure it wasn't a new book then. I don't remember the title or author of the book but I do remember the most of the plot so I really hope someone can help me find it again so that I can read the next book. It has a girl protagonist with a 3 (III) tattooed on the back of her neck hiding the number seven (VII) (or was it the other way around?). She is actually of low class but because she looks the same as the princess? (who was killed or lost or something), she is brought in to act as her. The number tattooed on their necks represents the class they are in in their society. Events occur, she has a fiance (actually the missing princess's) there is a part where she sneaks though some vents, does something to get herself into this camp place where people wear those overalls, does factory work, some people have to fight off in an arena at that place, there is a secret committee planning an uprising, she leads/is asked to/needs to the uprising, something happens, she gets taken to this castle-ish-not quite- place by her not-really-fiance, violence occurs, flee though underground tunnels, at the end, she and her not-really-fiance who has kidnapped her/ is in the castle-ish-not quite- place with her find out that there is another person pretending to be the princess as well which they view on a TV and that's where the story ends. The book cover, as depicted in this topic title is dark with an eye on the cover and numbers in roman numerals (I think it was a seven -> VII) inside of the eye. Perhaps a silhouette of a girl or maybe not (I might be mistake about that).
Hope someone can help me find this book again.
Happy reading.
- Lax

Lax, would you call this a YA dystopian or fantasy series?

I’m pretty sure it was a dystopian YA series.

Pretty sure it's shades children by Garth nix

for the link.

Adara, thanks for the suggestion. I searched it up but I don’t think that’s the one. The protagonist in the story I’m looking for is a girl and I’m pretty sure she’s older than 14. But you’re right, the cover does have an eye with numbers but I think it’s like black (from my memory) and smaller.
Thank you for your help regardless.

I hope this is right, it was one of my favorites when I first read it.
Pawn

Omg. Yes! That’s the one. Thank you so much Brooke (and everyone else who commented on this feed). I’m gonna read the next book now. 🥰

I knew I had seen this book, but for my life couldn't remember which one it was.

Now it is also in my list. Thanks, Brooke!