has16m is false but terminal supports Truecolor

I found this issue using chalk, but it’s color support related so I thought it was a better idea to submit my issue here.

Check out the following code. The same string is colored using the default chalk instance, a chalk forced to level 2, and a chalk forced to level 3.

// Default chalk
let chalk = require('chalk');
console.log(chalk.supportsColor);
print(chalk);

// 256 colors chalk
let ch256 = new chalk.constructor({level: 2});
print(ch256);

// Truecolor chalk
let ch16m = new chalk.constructor({level: 3});
print(ch16m);

function print(c) {
    let result = '';
    for(let i =0; i < 60; i++){
        result += c.rgb(255 - 2*i, 0, 2*i)('█');
    }
    console.log('    ' + result);
}

The supportsColor returns this: { level: 2, hasBasic: true, has256: true, has16m: false } , so it looks like my terminal does not support Truecolor.

However, the printed colors look like that:

It is clear that my terminal actually supports Truecolor. Why is it not detected ?

What if I always force level 3 in my code ? Can it impact users who only support 256 colors ?

Thanks a lot

---

supports-color version: 2.0.0 chalk version: 2.0.1 Ubuntu 16.04.2 LTS gnome-terminal 3.18.3

[sindresorhus]

@Delta456 https://blog.sindresorhus.com/issue-bumping-e3b9740e2a0

[Qix-]

There’s no way we’re bringing in a native module to supports-color, sorry.

Unless the terminal emulator exposes a way for us to detect the truecolor support (since traditional ways such as terminfo have not evolved to keep up) there’s nothing actionable we can do.

We’ve not heard back in over a year so I’m going to close this since there’s nothing (currently) actionable.