Two relevant and important rules of life here:
1. If you have to ask the question "is this creepy" then it probably is. Obviously everybody has a different threshold for creepy, but if your gut instinct has made you wonder, it's probably going to be creepy to some people. Being creepy is one of those things where it's worth taking zero risk.
2. If you're going to give someone a romantic compliment, it has to be something meaningful and relevant to them. Not something that sounds like a stock phrase. Saying someone's eyes are blue as the sea blah blah when their eyes aren't blue is a total reveal that you've just come up with the phrase hoping to sound good rather than being genuine. A girl I know went on some Tinder dates with this guy who sent her his "A to Z of why I want to date you"....at first she thought this was the sweetest thing, then after she read them a couple of times she was like hmmm, these just sound generic, I get the impression he sends these to every girl he chats to, and that actually put her off him.
Another general point - there are a lot more points to be gained with a girl by being authentic than by trying to impress. Girls can sense when you're coming out with a line trying to impress or just behaving in an attention-seeking way or whatever and whilst it might seem cute in that she'll like the fact you're obviously trying to impress her, that sort of behaviour always runs the risk of being creepy or cringey. The worst risk is, if she thinks its a bit OTT and tells her friends (and bear in mind girls tell their friends a lot) then her friends might laugh and you become a 'joke' amongst them, and thats bad news for your chances with her once her and her friends have turned you in to an anecdote.
Don't actively try to impress a girl just act naturally and have her best interests at heart and you will come across as authentic which is a lot more credible than writing any corny lines or lovey dovey gestures.