Fix ANSI color constants
Fix ANSI color constants

The `m` acts as termination-symbol when declaring graphics. Because
of this, the `;1m` doesn't have any effect and is directly printed to
the console:

```
$ nix repl
> builtins.fetchGit { /* ... */ }
{ outPath = "/nix/store/s0f0iz4a41cxx2h055lmh6p2d5k5bc6r-source"; rev = "e73e45b723a9a6eecb98bd5f3df395d9ab3633b6"; revCount = ;1m428; shortRev = "e73e45b"; submodules = ;1mfalse; }
```

Introduced by 6403508f5a2fcf073b2a0d4e5fcf5f5ebb890384.

rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,NixOS/nix,rycee/nix,rycee/nix