Almost everything looked like this in the 90s:

https://en.wikipedia.org/wiki/Jazz_(design)

The 90s was Pop Art

Vaporwave is that

Doc Martens and flannel. Can you smell the grunge?

It’s kind of earlier, but a little bit would be casette futurism.

https://tvtropes.org/pmwiki/pmwiki.php/Main/CassetteFuturism

A technological aesthetic reminiscent of mid-1970s to late 1990s tech (regardless of the real-time setting of the media) as codified by early microcomputers like the Altair 8800 and the IBM Personal Computer, late Cold War era technology, the iconic imagery of the mid to late space race, or the post-Cold War “end of history” period in The '90s, which was characterized by a fascination with virtual reality technologies (such as helmets) and 2D computer animation.

Whether it be the bold colors and geometric shapes, the tendency towards stark plainness, or the exotic-looking computers and proto-cell phones, it is clear that this is neither the Raygun Gothic of days past nor the Everything Is an iPod in the Future aesthetic that would follow, but a bridging point that contains elements of both styles.

Amazingly, nobody appears to have done a Wikipedia page for cassette futurism yet, or I’d link to that.

EDIT: Here’s a DDG link to an image search for cassette futurism, to sort of give an idea:

https://duckduckgo.com/?t=h_&q=cassette+futurism&iax=images&ia=images

Nu-metal buttrock played by white guys dressed like cholos.

It’s only denim.

Depends on which part of the 90s. That whole “deep space nine” color palette was huge in the early 90s — lots of maroons and mustards and dark grays.

Dockers pale brown/green, wool, plaid.

Synthwave was the result of taking futurist stuff from the 1980s, and then decades in the future creating a nostalgic 1980s retrofuturism-themed theme combining various things like Tron and Outrun.

So I guess that the closest analog would be looking for aesthetics from movies that were aiming for a futuristic vibe in the 1990s, then combining those.

https://old.reddit.com/r/scifi/comments/1bauod1/in_retrospect_1990s_scifi_film_had_a_very/

In retrospect, 1990s sci-fi (film) had a very distinct style.

At the time you couldn’t really tell, but looking back at the body of work that came out during that time, there was a very distinct style…and that style was apparently rust, lots of tubes connecting everything and up close shots with a fish eye lens.

Spaceship? Make it as rusty and dark as possible.

Medical scene? Connect her to 75 tubes to nowhere.

Getting chased down a corridor? Fish eye, baby.

I swear this is like every other sci fi film from 94 until 2000. A lot of it is almost reminiscent of horror.

70’s sci fi was still the era of tin foil and white jumpsuits. (Logans Run, Zardoz, etc. Star Wars was the exception, not the rule.) 80’s sci fi was darker and grittier and more serious looking drama, heavily influenced by Star Wars and Alien at the end of the 70’s. (TWOK, Blade Runner, Aliens, etc.) A lot of that mid-late 90’s stuff was leaning into horror, and kind of continuing a trend of the 80’s darker sci fi popularity. Then by like 2009, you had the Apple Store aesthetic in the Star Trek reboot where the style was “the future’s so bright you gotta wear shades.” It was all lens flares for a few minutes.

So I guess maybe it’d have more of a horror vibe than synthwave?

I don’t rightfully know, but my heart says “The hotwheels logo”

Unplugged.

The movie Hackers.

It’s The Matrix

Small yellow cars with black racing stripes, ear shattering sound system and massive wing spoilers…wicked!

Incredible!