Those softer greens have been around a while now. However, they've primarily been used on sites or companies in the medical field.
Nonetheless, let's say that a designer from DAN did happen to come across your site or lander. Then, they modeled theirs around yours. There is no real theft here, unless you're well well established (See:
Some established colors that were even used in lawsuits).
I would lean with
@MapleDots here and tell you the same thing: You should be flattered. And if you truly believe they copied you and you feel that one aspect of their site is better than yours, strive to retool your site to be more fitting.
I did not check the Wayback Machine to compare; I'm taking your word for it.
They even copy my ways of payment, I have 3 ways to buy a domain and wanted to add the 4th but the plugin is not available to work as I need.
1.BIN
2.payment plan
3.make a offer
4.leasing (not added)
Recently I have limited the view of domains because I decode their nature and bots from allot of different company come and crawl more than 1000 times per day the whole web, and I m tired of them, then I find later on their websites my combination of words I use.
People even copy my words and phrases on the other forum and on whole internet I can detect easy what's mine, socially distancing for 20 years make you very receptive.
The purple color which is used everywhere is taken from one of my logo, in short I have cursed the whole world because of grabbers before covid, I even can say how exactly I cursed and how the virus escaped, because Chinese are the biggest grabbers in the world.
The Navy blue color on iPhone was added because I regged 2 domains directly related to this color, because my email was at apple and I know they spy in peoples emails. I even gave them the idea of camera stabilization which was added in new iPhones, I could make them even better but they not want to deal with me because I m too right for their left agenda, in fact most today companies even don't need to hire staff because for them is easier to spy and steal ideas/inventions and this is where all it goes with 5G tech.
Yes I do recognize I m a bit obsessed with this, but it is due to the fact that I had to fight for my work with the users of my content, before investing into domains I was doing tech solution for iPhones, still having it to the moment, those solutions include around 30 different colors, of course most are not created by me but the daily usage of them are making them popular in human eye.
Anyway I not want to extend this topic it's better to close it.
P.s. there are around 10% of creative people in the world the rest are copycats.