Also of interest, would be the first OS to support color graphics in other ways (assuming it wasn't a Unix).

Background: I'm thinking of playing around with Unix v6 due to all the material available, but am curious if attempting color graphics in any form are worth the effort.

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    "Supporting multiple colors" is not an OS function, it's a function of the output device and the software driving it (which may or may not be part of the OS). It might make more sense to ask about the first computer generated colour output (probably some plotter with two or more pens), the first computer generated raster colour picture on a CRT, the first colour terminal, the first terminal capable of colour graphics, etc. Dec 20, 2020 at 9:16
  • Yes, if I catch your meaning, I realize it was largely coupled to hardware support, and it wouldn't make much sense for an OS to support color of any time if the hardware didn't exist, or at least if the OS itself wasn't targeted to run on such hardware. So must likely I was thinking about color terminal support, as to my mind that seemed the most basic, though as @RichF pointed out, other creative solutions involving separate displays seemed to exist.
    – bbarker
    Dec 20, 2020 at 16:00
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    Even so, you can do colour output without specific colour support in the OS or the terminal driver -- just send the right byte-sequence (coded into your application program) to the terminal.
    – dave
    Dec 20, 2020 at 16:45
  • Perhaps the first commercial color graphics output device was the Calcomp plotter, from 1959: en.wikipedia.org/wiki/Calcomp_plotter
    – jamesqf
    Dec 20, 2020 at 17:26
  • 2
    Look into termcap. Dec 20, 2020 at 22:02

2 Answers 2


Depends on what you mean by "OS support".

Early Unix (and all other OS) used video terminals that replaced the teletypes of even earlier Unixes.

These video terminals started supporting graphics and a bit later also color graphics. The first color graphics video terminal from DEC was the VT241 with Regis and Sixel graphics from 1983. BTW, Sixel graphics still work in many Linux terminal windows on modern systems.

An early color graphics IBM video terminal (non-Unix) is the IBM 3179G from 1984.

I am sure there were others.

These graphics worked by sending with special escaped character sequences, so any "OS support" (if present at all) consisted in libraries that applications could use.

The X Window System that became the standard for Linux appeared in 1984 (and was probably not very usable right then), The X11 protocal variant that it finally settled on was defined in 1987.

Unix v6 is a lot earlier than all of that. Of course you could still compile and run applications on your Simh-emulated Unix v6 that then send Sixel codes to the xterm you've attached to Simh. Just don't expect any GUI.

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    Looks like ReGIS was introduced in July 1981 with the VT125, per en.wikipedia.org/wiki/ReGIS (I don't know whether the VT125 had color, but the VK100 GiGi from 1982 did).
    – LAK
    Dec 20, 2020 at 15:07
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    @LAK according to the list here, the VT125 didn't have color.
    – dirkt
    Dec 20, 2020 at 15:38
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    I can definitely say the VT125 was monochrome (I cared a lot about terminal characteristics at the time). FWIW, ReGIS colour was also available on the Professional 3xx series.
    – dave
    Dec 20, 2020 at 16:49

Probably wasn't a Unix release per se, but the GUI you happened to use,such as raw x-windows (which would be my guess). There were other GUI's layered on top of x-windows, and it wouldn't surprise me if there were GUIs predating x-windows.

Initially, as I'm sure you know, Unix was solely a console-controlled OS. So the first color available would likely have been color terminals, with programs and scripts making use of ESC sequences to implement color into their work.

  • Colour graphics (as opposed to text) output surely pre-dates the use of GUIs.
    – dave
    Dec 20, 2020 at 12:24
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    @another-dave One early option was a separate monitor for graphics output. You would control everything from a terminal, but if you wanted to display graphics, it would be sent to the RGB display. I worked on a Forth and RTX-11 system in the early 80s that was configured thusly. I'm sure similar Unix set-ups existed. Note that the OS had little if anything to do with the RGB monitor; anything seen on it was from an application program.
    – RichF
    Dec 20, 2020 at 13:03
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    Indeed. ICL 1906A, ASR33 terminal, some Tektronics vector display, in my case. But the only colour was green.
    – dave
    Dec 20, 2020 at 13:41

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