Bug#953527: [apt] colour highlighted error/warn labels

[jnqnfe@gmail.com]

Hi, Julian,

Thanks for adding the colour support in apt 2.0.1.

I'm curious though, most implementations use isatty() to determine the
default colour control setting, which it seems that your implementation
lacks, instead only outputting colour when explicitly enabled via `-o
APT::Color=true`.

Was it a deliberate decision to not make use of isatty() to determine a
default?

Regards,
Lyndon