Dark theme for custom formatters in devtools dark mode

I'm not sure how custom formatters work, but the logs are currently hard to read when devtools is in dark mode. I imagine the colors are customizable, but it would be nice if the default formatters had a config option for viewing in dark mode (any dark foreground colors would be swapped with lighter ones).

The issue does not name any files, tests, or entry points. Start by researching how custom formatters expose colors to Chrome DevTools and how DevTools dark mode is detected; define the configuration behavior and verify that default formatter output remains readable in both themes.

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