Peter Jackson’s “They Shall Not Grow Old,” his much-ballyhooed colorized documentary of World War I from the British Tommy’s trench–eye-view of the fighting, almost lives up to its hype.

It is immersive, letting us hear and feel the concussion of artillery, if not the whistling hail of bullets and the desperation and fury of hand to hand combat.

This is very old and for any History Channel or PBS or even CBS viewer — which broadcast hours of this stuff on TV in the ’60s — somewhat familiar footage, British Imperial War Museum black and white, 18 frames-per-second newsreel and government documentary footage of what “The Great War” was really like — 100 years ago.

Jackson edits this material into a bottom-of-the-ranks look at this “War to End All Wars,” screening it over archival oral history interviews with legions of unnamed survivors — recordings probably from the late 1950s or so, from the sounds of the men.

It paints a fairly thorough view of the British experience of the war from the view of the men who fought it. The myopia of the trenchworks, the narrow focus of “staying alive” and “having a job and getting on with it,” the very essence of keeping calm and “carrying on,” means that we see no maps, hear no historians declaiming the strategies, the ebb and flow of the war, or even the arrival of the Americans — which turned the tide in 1918.

These fellows had no experience of that, and when the Armistice was announced, they admit there was “no cheering” or celebrating, no feeling of “We’ve won.” Just exhaustion, followed by relief followed by bitter disappointment upon returning home.

One soldier recalls being accosted by women in 1914, harassed with “Why aren’t YOU in uniform?” One slipped a white feather, denoting cowardice, onto his person. There was no British “Lysistrata,” women taking the lead in preventing slaughter. Patriotism among those with no risk of being exposed to combat was universal.

What Jackson wanted to do was turn New Zealand’s digital effects wizards loose on a process that Ted Turner made infamous 30 years ago, ruining “Casablanca” and other black and white classics for his TV networks. Jackson’s team was working with much rougher footage, jerky motion due to the 18 (and not 24) frames per second exposure of hand cranked film cameras, washed out images due to the conditions of filming, faces often indistinct if the man being photographed turned his head while being filmed.

Much of that is corrected, and the colorized sequences — establishing shots of marching to the trenches, crawling into them, or rest and recreation scenes when the men were off the line — with dubbed background noise (a preacher giving a funeral sermon, officers giving pep talks, enlisted men bantering) can be impressive.

But quite often the colorized faces seem to drift clear of the footage they’re being superimposed upon. Sprints across No Man’s Land are disembodied, surreal with movement that isn’t remotely human. Explosions look like early TV efforts to videotape fire, fireworks and bomb blasts — diffuse, with an effect smothering what the camera actually captured.

Most impressive are the first tanks and the squat, thunderous howitzers of the day. We’ve never seen these British-invented tanks in their olive drab combat colors, and the jolt of the cannon — one moment has the mere noise blowing tiles off the roof of a nearby French barn — are impressively goosed by adding sound with impact.

It takes its title from the “Ode of Remembrance” portion of the famous “Remembrance Day” poem by Laurence Binyon, “For the Fallen.”

“They shall grow not old, as we that are left grow old:
Age shall not weary them, nor the years condemn.
At the going down of the sun and in the morning,
We will remember them.”

So the larger aim here wasn’t so much the “in living (nope) colour” gimmick. This was a generation wiped out on the miscalculations and whims of unrepresentative governments. Jackson wants to pay tribute to those who served and those millions who fell, and cannot help but sentimentalize them, just a little.

A short film of American participation in the war, narrated by Gary Sinise and supporting a US World War I memorial, accompanies this Fathom Events presentation of Jackson’s Warner Brothers production.

I could not help but be moved by the seemingly senseless tragedy, the scale of the horror, which the survivors would only describe as “tension” on those rare occasions when the folks back home wanted to know what the soldiers went through.

Adding color to the carnage of bleeding men, trench foot treatments, smashed corpses and dying horses just underscores the awfulness of it all. Seeing it in 3D will heighten the immersive nature of it all.

But every so often — more often than you’d like — the hyped colorizing looks like rotoscoping — animator Ralph Bakshi’s way of filming “The Lord of the Rings” in the ’70s, Richard Linklater’s “Waking Life” a more recent example. That gives “They Shall Not Grow Old” an impressionistic touch, as Jackson mixes still drawings, recruiting posters and the noble black and white footage to frame the story he tells in largely washed-out colors.

That distracts and lets the effects rob what they’re depicting of some of the power that these images still hold for those who don’t need them colorized to remember the nightmare an entire “lost” generation — killed, wounded or brutalized in other ways — endured. The whole is rather less impressive than the hype (there’s a “making of” short film after each showing) would have us believe.

MPAA Rating: R for disturbing war images

Credits: Directed by Peter Jackson. A Warner Brothers release.

Running time: 1:40