Terminal.app for macOS Tahoe supports truecolor

[dibenzepin]

I'm currently running the developer beta for Tahoe and it does in fact support truecolor (i'm not sure if it advertises the env vars though...haven't checked).

Here's a MacRumors article about it from the WWDC announcement: https://www.macrumors.com/2025/06/16/apples-terminal-app-macos-tahoe/

and here's how colors.py looks:

it doesn't seem to support the underline though, but the blinking works (ghostty doesn't blink even)

[kurahaupo]

For the sake of anyone else reading this, the link shown in the image is https://gist.github.com/lilydjwg/fdeaf79e921c2f413f44b6f613f6ad53/raw/94d8b2be62657e96488038b0e547e3009ed87d40/colors.py

[kurahaupo]

@dibenzepin whilst it appears to accept CSI 38;2;R;G;Bm, can you confirm that it's really using TrueColor and not approximating to a limited palette?

(I ask because in the past several terminal emulators have accepted 24-bit color escape codes so while actually approximating the displayed colors using an internal 8-bit palette.)

[dibenzepin]

@kurahaupo how would i confirm that? it looks pretty similar to ghostty's and the "true colors gradient" is an actual gradient

[dibenzepin]

i've also run these commands from the readme (black background is terminal.app, purple is ghostty):

[dibenzepin]

it also does set the env var:

as opposed to ghostty's

[kurahaupo]

The sample with the leaning matchsticks shows only 77 samples, which means it doesn't show enough to distinguish 8-bit colours 24-bit colours.

There are several other ways to check:

1. print a test pattern using just colour (not b&w) with as many brightness steps as you can accommodate. Examine it carefully by eye, and make sure there a no obvious steps.
2. set a 24-bit colour, print a char, move the cursor back to that char, and ask the terminal to report its colour. Read the response as if it was keyboard input.
3. print a test pattern using 24-bit colour codes, and then load a new 8-bit colour palette with obviously different colours. If the pattern already on the screen changes colours, then it's using the 8-bit palette; if not, then it's probably using 24-bit colour.