Baroness is a rare band in the metal genre, in that they are constantly recreating themselves and redefining their sound.

Baroness is no stranger to blending disparate metal archetypes into new and vibrant sonic vistas. Although their early work relied on a denser, more purely metal sound, the Savannah, Georgia outfit reached a pinnacle of critical acclaim in the early aughts–making a name for themselves with an innovative combination of prog and noise rock, while still remaining firmly rooted in the sludge metal sound of their origins.

Their last album, 2015’s Purple, brought the band into mainstream rock consciousness, catapulting them far beyond their status as the underground kings of progressive metal. Purple was adored by rock/metal critics and longtime fans alike; it even landed them a Grammy nomination. Anyone who follows the world of metal closely knows well that this is an extremely difficult line to walk–to make music that is heavy, loud, and honest enough to excite the metalheads while also being polished and commercial enough to be considered for a Grammy.

With nearly four years and a significant lineup change between the band and Purple, their latest release, Gold & Grey, has been one of the most highly anticipated prog rock albums in recent years. This record marks both the end of the band’s color-themed records, seeing as—alongside Red, Blue, Green & Yellow, and Purple—Baroness has officially covered the full spectrum of the color wheel. Well, kind of. Orange would have technically been the final color, but as the band’s front-man (as well as the artist responsible for all of Baroness’ album covers), John Baizley explains to Revolver‘s Sammi Chichester, “[Orange is] the most gaudy hue that is available […] It’s 100 percent why we haven’t done that color yet. We kind of saved it for last.”

However, Baizley goes on to hint that perhaps the combination of gold and gray could somehow imply the color orange, or perhaps strip it of its so-called gaudiness. “I was going out to see a show, brushing my teeth in my bathroom before I went out […] The walls of my bathroom are this sort of warm, neutral gray. I had a pack of Trident—like an orange, mint-flavored gum. As I lifted the package out of my pocket, I saw that package with the walls behind it. The color combination was so intriguing. It just hit me like a ton of bricks. I said, ‘This is the way to do it. There’s a gray element.'”

Synesthetic interpretations aside, Gold & Grey is yet another departure for a band that seems to be constantly departing. In fact, with each new release since Red, Baroness has been gradually inching away from their sludge metal roots, one small step at a time. 2012’s Yellow & Green marked the band’s first significant turn from a more firmly metal-oriented sound, allowing themselves to more fully explore the ambient and sonically experimental realms of progressive music. And since then, each new release seemed to leave the metal further and further in the past. Gold & Grey, however, marks the first time Baroness has come close to nearly abandoning that heavy sound all together.

The moments when that classic Baroness heaviness can be heard on Gold & Grey are fleeting—more like an allusion to their metal roots than a full-on embrace of them. The heavy metal purists are likely to skip through much of this album in search of something to bang their heads to. There is still some solid riffage, though, particularly on tracks like “Front Toward Enemy,” “Borderlines,” “Throw me an Anchor,” and “Tourniquet.”

The majority of Gold & Grey, however, sees Baroness reveling in ambiance, synth-driven prog rock, and, perhaps most uncharacteristically, acoustic songs with more traditional structures and chord progressions than fans have come to expect from the band. Songs like the piano-led, vulnerable ballad, “I’d Do Anything;” the mellow, twinkling, and lonely sound of “Emmet – Radiating Light;” and the indie-inspired instrumental interlude, “Blankets of Ash,” all see Baroness moving toward more emotionally wrought and stripped-down places than they have ever gone before.

Gina Gleeson, in addition to providing stellar guitar work, has lent Baroness some new dimensions. Not only does she shred, but it sounds as if she may have been responsible for pushing the band into some very interesting and unexpected places. Another element, for example, that stands out about Gold & Grey, is how solid and, for lack of a better word, sturdy the vocals sound when compared to previous Baroness projects. This is, in part, due to Gleeson’s expert backup vocal work. She lends many rich yet understated harmonies to Baizley’s singing, adding a new heightened level of musicality and emotional depth to the band.

Gold & Grey is not your typical Baroness album. But, then again, there really is no such thing as a typical Baroness album. This album, though, definitely does mark the end of an era for Baroness, and it is a perfectly colorful sendoff–an album as sonically and vibrantly solid as it is authentic and dark–equal parts gold and grey.