Your post kickstarted a rework of how I theme things, so thanks for that.
I'll suggest one thing though: using color-mix to generate palettes based on a key color value.
For example, your danger palette could be written like this, basing the key value on the built-in --error:
--palette-danger: var(--error);
--palette-error-0: color-mix(in srgb, var(--palette-error) 0%, white);
--palette-error-50: color-mix(in srgb, var(--palette-error) 10%, white);
--palette-error-100: color-mix(in srgb, var(--palette-error) 20%, white);
--palette-error-150: color-mix(in srgb, var(--palette-error) 30%, white);
--palette-error-200: color-mix(in srgb, var(--palette-error) 40%, white);
--palette-error-250: color-mix(in srgb, var(--palette-error) 50%, white);
--palette-error-300: color-mix(in srgb, var(--palette-error) 60%, white);
--palette-error-350: color-mix(in srgb, var(--palette-error) 70%, white);
--palette-error-400: color-mix(in srgb, var(--palette-error) 80%, white);
--palette-error-450: color-mix(in srgb, var(--palette-error) 90%, white);
--palette-error-500: color-mix(in srgb, var(--palette-error) 100%, white);
--palette-error-550: color-mix(in srgb, var(--palette-error) 90%, black);
--palette-error-600: color-mix(in srgb, var(--palette-error) 80%, black);
--palette-error-650: color-mix(in srgb, var(--palette-error) 70%, black);
--palette-error-700: color-mix(in srgb, var(--palette-error) 60%, black);
--palette-error-750: color-mix(in srgb, var(--palette-error) 50%, black);
--palette-error-800: color-mix(in srgb, var(--palette-error) 40%, black);
--palette-error-850: color-mix(in srgb, var(--palette-error) 30%, black);
--palette-error-900: color-mix(in srgb, var(--palette-error) 20%, black);
--palette-error-950: color-mix(in srgb, var(--palette-error) 10%, black);
--palette-error-1000: color-mix(in srgb, var(--palette-error) 0%, black);
There are a few more nuances but don't mind those. Here's a comparison, the top one is using this palette, the bottom one is the danger palette you posted.
There might be a better color space to use with color-mix, or maybe it can be parameterized better, but I still have to dive into this.
Now, This may not be game changing for you, as you already have a full css setup and I believe, some processing to generate your css, but for someone who wants to start creating palettes, this can change the whole game, especially if you base your key colors on built-in colors, then the whole thing sticks to the theme without having to actually touch theme files.
edit:
error, warning, primary, success and neutral, based respectively on --error, --warning, --info, --success and --neutral-50
