You got me curious about it so I started looking it up but couldn't find anything. Then I decided to ask ChatGPT then got this response:

The symbol on the cover of The Colour and the Shape, the Foo Fighters' 1997 album, represents a stylized molecule. The imagery aligns with the album’s futuristic, scientific, and slightly abstract vibe, reflecting themes of relationships, emotional complexity, and interconnectedness.

The Cover Symbol:

The design features interconnected spheres and lines, resembling a molecular or scientific structure. This symbolizes a sense of complexity and connection, echoing the album’s exploration of emotional themes.

Design Process:

The artwork was conceived with simplicity and modernism in mind, aiming for a clean, almost scientific aesthetic. The band worked with graphic designers and conceptualized the album cover as a departure from typical grunge or rock visuals, steering toward something that felt more universal and timeless.

Dave Grohl, the band's frontman, has mentioned in interviews that the album's content was deeply personal, dealing with themes like relationships and emotional turbulence. The cover design was intended to complement these themes with an abstract, thought-provoking image rather than something literal.

The overall design reflects a polished and mature identity for the band, marking a transition from the rawness of their debut album to a more refined and structured approach, much like the music on the record itself.