For a £1000+ unopened device, 14 days is pretty terrible...
When Apple gets an unopened device return they'll have to verify it just the same, open up the box to make sure it was actually unopened, and I assume if they determine they can sell it again as brand new they'll at least have to use a new box and seal that so it looks no different from other new phones.
I understand the frustration with the color choices, however the color comparisons in videos should be helpful enough, and if not you can always go to a store and look at the colors in person. (And if you pre-ordered it you could still have checked the colors in a store by now...)
It's not like you could end up with an ugly color, if you prefer something bright you get just two choices and there are only two dark options as well.
In over two decades now of owning Apple devices not once did I return an Apple product. The only regret I had was getting a product in space grey when that color choice was made available for the first time. But then it took me a while to dislike it and I wouldn't have dreamed of exchanging it just because the color wasn't perfect for me. I usually look at the display, not at the back.
You started the process online so your consumer rights should still apply.
This might differ on where you live but here the law determines this by looking at where you made the purchase. If you paid online with your credit card and then picked it up in a store later, it was a purchase made online and is thus covered by the laws applying to purchases over the internet. If you picked it up in a store and paid right then and there, the online reservation would not count as an online purchase.
You can usually tell by whether you got a reservation confirmation or an actual invoice. If you get a proper invoice online then I believe it counts as a purchase made online, no matter where or how you pay for it. But since online buyer protection is usually better, this is the reason why when you pick something up in a store you only ever get a reservation confirmation and not an invoice. This is so that the merchant can avoid having the sale classified as an online purchase. On the flipside you are also under no obligation to pick up the reserved goods.
(I had a silly store that would let you reserve something online to pick it up, and that was the only way to get the goods since they didn't ship anything at all. However, what I ordered was in very low demand and had a two week lead time. I thus went through the reservation prodecure and was told they'll let me know when it's ready. Contrary to that, a full week later I received a message saying they won't even order the goods without me doing a wire transfer first, because if I don't pick it up they have nobody else to sell it to. I then asked them for an invoice to make sure it counts as an online sale so I can return the product if necessary, and they refused. They asked for payment without an invoice. I never paid and never ordered anything else from them.)
I had iPad Pro m1 for nearly a month , once bought online returned, the other time bought in store returned
will do the same for the new iPhone
You yourself as well as all of us pay for that, Apple factors such returns into their product pricing. I wish they'd ban customers like you, why do I have to subsidize your habits of using products with no intention of actually paying for them.