name: create-theme description: Use this skill when the user wants a reusable house style for open-sheet workbooks — "make a theme with our brand colours", "all our spreadsheets should look like this", "create a corporate template". Writes themes/<id>.md and an optional demo workbook the gallery previews. metadata: version: "1.0.0"

Create a theme

A theme is a house style that workbooks link to with meta.theme. It lives as markdown so it is readable by both people and agents.

The file

themes/<id>.md:

---
name: corporate-neutral
description: Near-white, one blue accent, sans throughout.
---
 
# Corporate neutral
 
## Palette
| Token | Value | Used for |
| --- | --- | --- |
| ink | #0f172a | body text, table header fill |
| accent | #1d4ed8 | KPI values, data bars |
| band | #f8fafc | total rows, key-value fills |
| rule | #cbd5e1 | hairlines |
 
## Formats
Currency `#,##0` · Percent `0.0%` · Dates `yyyy-mm-dd`
 
## Paste-ready design const

export const design: DesignSystem = { … }

 
## Conventions
- Assumptions always on their own sheet, key-value
- Data bars on the primary magnitude column only
- Column widths: labels 24, figures 14

Optionally add themes/<id>.demo.tsx — a small workbook exercising the theme, so the gallery has something to show.

Rules that matter for print and Excel alike

• One accent colour. A second one competes; a third is decoration.
• White or near-white background. Anything darker costs toner and makes

Excel's own selection highlight unreadable.

• Body text no smaller than 10pt. Spreadsheets get printed and squinted at.
• Number formats are part of the theme. A house style that leaves ratios

unformatted has not done its job.

• Keep the design const a plain object literal so the Design panel can rewrite it.