What is wrong with the native `writeStream.getColorDepth`? #108

It didn't exist until recently and IIRC I've had some concerns with it.

It was also adapted from this package.

We don’t plan to use it as the benefit of this package is that the logic is stable across Node.js versions.

I just discovered one limitation… process.stdout.hasColors (or process.stdout.getColorDepth) is not always defined. For example, a spawned child process that is not a TTY will not have those methods on process.stdout or process.stderr.