Better NYTC от Steve Kieffer

In the Crossword:

• Hold shift to use pencil temporarily, double tap to switch.
• Optionally use Caps Lock to switch (activate via control panel).
• Use Alt-P (Option-P) to pause/unpause the timer.
• Activate dark mode from the puzzle's control panel (gear icon). Preserves yellow and blue highlights, and keeps shaded squares visible, while saving your eyes.
• Activate red pencil from the control panel, to make pencil stand out.

PLUS (starting with version 1.4.0) an optional dark mode toggle for the following games:

• Connections
• Letter Boxed
• Pips
• Spelling Bee
• Strands
• Sudoku
• Tiles

You can activate it from the extension's options/preferences page in your browser.