If you want an easy way to see how far Taylor Swift has come since her last album, just compare the covers of the previous one with her latest, the just-released “Lover” (Republic Records).

The 2017 releases “reputation” featured a photo of Swift unsmiling in black and white, while “Lover” is an explosion of color, clouds and sparkles.

The superb, new, 18-track collection finds Swift looking backward and forward through the lens of love — present and absent, lustfully and wistfully, friendly and concerned. She calls it a “love letter to love itself.”

It’s a remarkable look at the various hues love can take. A songwriter long associated with bright red is painting now in blues and golds.

“I want to be defined by the things I love — not the things I hate,” she writes in the album notes and repeats in “Daylight,” the final song.

For many of the songs, she’s reunited with producer Jack Antonoff. They’ve hacked away at a lot of the previous electronic clutter to show off Swift and her rich pop songwriting.

The album kicks off with the trip-hop “I Forgot You Existed,” which seems to refer to her old feud with once-friend Kim Kardashian, whom she slammed in “This Is Why We Can’t Have Nice Things.” Now, with genuine laughter, she says she’s just indifferent.

Most of “Lover” is exuberant, a return to the diaristic Swift of the past. She seems to revel in the hard-fought happiness she’s found with her boyfriend of three years, the Englishman Joe Alwyn, the obvious source of “London Boy.”

In the Go-Go’s-ish “Paper Rings,” she suggests “you’re the one I want,” while the album’s title track even contains Swift singing a mock wedding vow. On “Cornelia Street,” she’s frightened that one day he’ll walk away.

Last time out, Swift was a cool villain, settling scores. Now, she’s joyfully dueting with Brendon Urie of Panic! At the Disco on “ME!,” a slice of self-love. She’s refreshingly contrite on “Afterglow” and reaching out in the unaffected “It’s Nice to Have a Friend.”

There’s also a fair amount of tears, drunken regret and breakups and even a health scare in the understated ballad “Soon You’ll Get Better,” which features the Dixie Chicks, fiddle and banjo. “Cruel Summer” (with writing help from Vincent) and “Death by a Thousand Cuts” are about love gone bad — really, really bad.

There are interesting touches throughout, including a sax in “False God” and a cameo by Idris Elba (a snippet from “The Late Late Show with James Corden”). She name-drops Leonardo DiCaprio and Drake, while calling herself a “Tennessee Stella McCartney.”

“Miss Americana & the Heartbreak Prince” is the most ambitious track, reaching for something deeper than a high school moment.

Consciousness-raising has never been Tay Tay’s thing and with the exception of the pro-gay, anti-hating anthem “You Need to Calm Down,” Swift skirts politics. But she tacklea sexism’s double standards in the excellent “The Man,” angry that she gets pulled apart for the same behavior for which men are toasted: “I’m so sick of running as fast as I can / Wondering if I’d get there quicker/ If I was a man.”

The album ends with one of Swift’a most introspective songs, “Daylight,” on which she sings of waking from a 20-year dark night. Now, she can see “I wounded the good and I trusted the wicked.”