Should evaluate provide more colour support?

[hadley]

Imagine building this Rmd/qmd in RStudio (with colour support) to generate a PDF (without colour support):

```{r}
#| error: true
cli::cli_abort(c(x = "Error"))
```

```{r}
cli::cli_abort(c(x = "Error"))
```

The first error shouldn't use colour because it's emitted into the document; the second error should use colour because it's emitted into the terminal.