Stanza 5 Summary

Get out the microscope, because we’re going through this poem line-by-line.

Yet, as the sun acknowledges
With a warm look the world's hunks and colors,

Alas, these quiet moments can't last. The sun's gonna rise, and folks are gonna get up and get on with their day.
And that's just what starts to happen in these lines. The warm sun rises and lights up the world.
It's worth noting that the sun's getting personified here. In general, we don't think of a gigantic ball of nuclear energy being capable of acknowledging, well, anything. And it's doing so with a "warm look," as if the thing has eyes.
What's it acknowledging here? Hunks and colors probably just refers to all the things the sun lights up when it rises—hills, mountains, buildings, cars, trees, you name it.
"Yet" is an interesting way to start line 25. Maybe the soul will change its mind about what's about to happen? It's bummed for now, but maybe it'll perk up in just a bit.

The soul descends once more in bitter love
To accept the waking body, saying now
In a changed voice as the man yawns and rises,

The soul returns to the body. Finally. Sheesh.
This might sound like a happy occasion (reunited and it feels so good?), but it's described as a descent. Remember, the soul was hanging out above the body, floating around with the angels. Now it's gotta dive back in there.
But the soul's not totally displeased. Sure, "bitter love" seems like kind of an oxymoron, but if you think about it, the soul, being part of the body, probably does love and accept it, even if it drags the soul down from its heavenly transcendence.
"Once more" reminds us that the soul has gone through this before, so the outcome of these events probably seems inevitable. The soul will accept the body. But why?
Whatever the case, now that the soul finally accepts the body, we'd better brace ourselves for a shift in the poem, because the man is getting up. And what will happen to the angels then?
Oh, and the soul's about to say something else, so we'd better listen up.