No he isn't, he is neutral at best
Light could no longer pass as/was no longer a Utilitarian by the end of the show. He didn't keep doing what he did for "the greater good" (that was the case at the beginning, or at least what he used as justification till he got drunk with power). He did it because he developed a god complex. It's very clear in the story.
They'll just say "I'm doing this because I want more money/power/fun."
That's Light. He does want power & absolute control for the sake of having power, because he believed he dsererved it. His narcissistic trait was the basis for his evil transformation. He had no moral qualms doing a lot of immoral acts for self-gain. Again, the final scene shows it very clearly (along with many events prior to that). Everything he did was first and foremost in self-interest.
Light was
Lawful Evil.
A lot of people said he is lawful but I don't quite buy it. Using death note to enforce Justice in the beginning is a very classic chaotic good anti-hero trope. So he doesn't even believe in law, he opposed it.
So how can you possibly put him in chaotic category in the beginning THEN make him lawful in the end.
His own "personal code of justice" is also widely inconsistent which is overwhelmingly not a "lawful" trait. He can bent his own code of justice and use it differently when he sees fit. He went from "this is okay" to "this and this and this are all okay" in the story. If you are lawful you wouldn't do that.
Lawful is often being seen as inflexible precisely because a lawful characters will rigorously follow a code and wouldn't just change it for their need.
So IMO, it's quite clear that he is not in lawful camp.
As for whether he is evil or not, this has more room for debate. He does have narcissist personality. That's why he believe his personal code of justice is the absolute. This personal code isn't rooted in desire, it's rooted in his own ideology. And his god complex came from his confidence with his ability after he won his first battle against L. He developed his god complex
after he become successful and gained extreme confidence, not because he is born with a desire for power.
So I would see him as a chaotic neutral person who has narcissist personality, and his narcissist personality make him believe what he do is right and it should be enforced further, which makes him looks like he belongs to evil alignment on surface but not really.
He is definitely a VERY different type of character from Cersei Lannister for example. Cersei is IMO a classic power loving evil character that loves power for what it is.
Another classic example is Scar from Lion King. He loves power for what it is. Those characters doesn't need to find an ideology to justify their desire, they love power because power gives them good stuff.
Verdict: Light Yagami can not join my evil army, he is REJECTED. But Cersei Lannister and Scar can!