[Bug Report] Incorrect Colour Mapping on Konsole
### Version

Nightly

### Category

Visual ─ Output is hardly readable or not uniformly formatted.

### Steps to Reproduce

The bug always occurs with using either `example/moerc.toml` or the result of `moe --init` as configuration and KDE Konsole as terminal.

### Detailed Description

The terminal background colour is mapped to #F67400.  The default background colour of KDE Konsole is #232627.  Other colours are mapped incorrectly, as well, making the output hardly readable.

![Screenshot_20230707_153637](https://github.com/fox0430/moe/assets/92332892/eaa8c961-79b8-44fa-bd1c-b51b80e419fb)