Replace `1;38` with `1;37` (bold white) in the delimiter/header
color constant. SGR parameter 38 is the extended foreground color
prefix and requires sub-parameters (e.g. `38;5;n` or `38;2;r;g;b`),
so using it bare produces an invalid escape sequence. Most terminals
silently ignore the malformed parameter, masking the bug.
Fixescli/cli#12683
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
json.Marshal does HTML-escaping by default, which is what we don't want since we're printing to the terminal instead of embedding this JSON into a HTML document.
"null" was previously rendered in "bright black", an ANSI color that is
not guaranteed to be visible at all depending on the terminal. Switch
the color to cyan to ensure that "null" is visible.
