Fun fact: a huge chunk of our notion of retro punk aesthetic is based on a specific technical limitation of one particular computer graphics card.
In a nutshell, back in the early 1980s, the first widely available graphics card to support colour display was the IBM Color Graphics Adapter, which would later lend its name to the CGA video standard. Though in theory it supported sixteen simultaneous colours, doing so at an acceptable resolution required complex coding tricks that wouldn’t necessarily work on all platforms. In practice, the most you could count on was four colors – and what’s more, it had to be four specific colours. You had your choice of black/green/red/yellow, black/blue/red/white, or black/cyan/magenta/white. The black slot could sometimes be swapped out for a limited range of other colours, but the other three slots were fixed.
All three palattes saw use for various purposes, but for gaming in particular, the green/red/yellow palette was generally regarded as too garish, and the blue/red/white as too flat, so the cyan/magenta/white palette won out by default – and that’show we ended up with a generation of games that look like this:
Does that palette look familiar? It should – we slap it on basically everything that’s meant to evoke a retro 1980s aesthetic. But 80s fashion never actually looked like that: it’s literally just a technical limitation of one specific video card that’s become enshrined in our vision of the decade because a whole generation of video games was written for it.
Wouldn’t that palette in particular have been more popular for games after CGA’s heyday? Like, I heard that a lot of early CGA games were designed with composite mode in mind, and took advantage of the way NTSC artifacting would blend adjacent colors into new ones, and that designing with RGBI in mind was more common for games that came out after EGA and VGA became more commonplace, since their backwards-compatibility modes didn’t support composite video.
So if anything, it’s because of a specific technical limitation in later computer graphics cards’ ability to emulate that computer graphics card. Kinda like how our idea of what old games look like is based on how they look on modern monitors.
Pretty much that. NTSC composite was pretty dang inaccurate when it came to decoding color, often mistaking parts of the luma (black and white, “Y”) signal as being part of the chroma (color, “P”) signal.
As a glimpse into just how bad this was, pictured above is a screen of 80-column text (for reference, 40-column text is much more commonly used). On left is RGBI output. On right is NTSC composite output. Quite the difference, eh? As time went on, programmers figured out exactly which patterns produced which colors.
On top is a chart displaying common patterns used in 320×200 mode, palette 1 (the palette mentioned in OP, which like the other palettes has a high-intensity variant); on left is the patterns, on right is approximately what colors they produce. On bottom is Ultima 2 running in this mode, RGBI on left and composite on right.
640×200 mode is quite a bit trippier in this regard, because it’s monochrome! As with the previous such image, the patterns themselves are on the left, with the colors they produce on the right.
This game, King’s Quest, uses that mode for its composite mode. Above is its composite mode, below is its RGBI mode. Left is its output on an RGBI monitor, right is its output via composite.
That’s absolutely true, though it’s important to note that this technique was never as popular as a lot of sources make it out to be. It was finnicky to set up and unreliable in execution if the user’s display was miscalibrated even a little bit, so most games of the CGA era used the standard palettes straight – as evidenced by the fact that their graphics lack the characteristic dither patterns used to achieve off-palette colours in composite video mode.
Still, in the interest of completeness you’re totally right; in addition to those games that used the cyan-and-magenta palette straight, CGA-era games that employ composite colour techniques may incorrectly be displayed with cyan-and-magenta graphics when played on later-generation hardware that lacks composite video support, adding to the palette’s apparent ubiquity.
Plot Designing 