visual-brand-extractor（视觉品牌提取器）

Visual Brand Extractor

Extract a client's visual identity from their website and generate reusable style presets for slides and content assets. This is an agent-executed skill — the AI reads pages via WebFetch and performs the analysis directly.

Quick Start

Extract visual branding from https://vapi.ai for the Vapi client.

Inputs

Output

Two files saved to clients/<client-name>/brand/visual-identity.md:

1. Slide preset — CSS custom properties, typography, and signature elements matching the format in skills/create-html-slides/STYLE_PRESETS.md
2. Brand config JSON — Simple color/font config matching skills/content-asset-creator format

Process

Phase 1: Fetch Target Pages

Fetch 2-3 pages to get a representative sample of the brand:

1. Homepage (mandatory) — the primary brand expression
2. Product/feature page (if available) — deeper color and layout usage
3. Blog or about page (optional) — secondary design context

Use WebFetch on each URL with a prompt like:

"Extract the full content of this page. I need: all color values (hex, rgb, hsl), font family names, CSS class names (especially Tailwind utility classes), any CSS custom properties/variables, meta tags, and the general structure of the page layout. Preserve exact color codes and font names."

Phase 2: Extract Color Palette

Analyze the fetched content to identify the color palette. Look for these sources in priority order:

2.1 CSS Custom Properties

Look for :root, html, or body blocks containing color variables:

--color-primary, --primary, --brand, --accent
--bg-*, --background-*
--text-*, --foreground-*

2.2 Meta Tags

Check for:

• <meta name="theme-color" content="#..."> — often the primary brand color
• <meta name="msapplication-TileColor" content="#...">

2.3 Explicit CSS Color Declarations

Search for color values in these properties:

• background-color, background (including gradients)
• color (text colors)
• border-color, border
• box-shadow (accent/glow colors)
• fill, stroke (SVG logo colors)

2.4 Tailwind Utility Classes

If the site uses Tailwind CSS, map utility classes to hex values using the reference table below.

2.5 Classify Colors into Roles

2.6 Determine Theme Type

Check the luminance of bg-primary:

• Dark theme: Dark background (black, navy, charcoal) with light text
• Light theme: White or cream background with dark text
• Mixed: Note if the site uses both (e.g., dark hero + light content sections)

Phase 3: Extract Typography

3.1 Find Font Sources

Look for font loading in this order:

1. Google Fonts <link> tags — Font name is in the URL: fonts.googleapis.com/css2?family=Inter:wght@400;700 → Font: Inter, weights: 400, 700
2. Fontshare <link> tags — Similar URL pattern: api.fontshare.com/v2/css?f[]=clash-display@400,700 → Font: Clash Display
3. @font-face declarations — Extract the font-family value
4. font-family CSS properties — Direct declarations on elements

3.2 Classify into Display vs Body

If both use the same font family, it's a single-family pairing (like "Manrope + Manrope"). Note the different weights used for display (700-900) vs body (400-500).

3.3 Handle Proprietary Fonts

If the site uses a font NOT available on Google Fonts or Fontshare, map it to the closest available equivalent using the Font Fallback Table below.

Phase 4: Analyze Visual Patterns

Examine the CSS and page structure for these aesthetic signals:

Synthesize the Vibe

Based on the signals above, compose:

1. Vibe: 2-4 adjectives (e.g., "Clean, technical, developer-focused, modern")
2. Layout description: 1 sentence (e.g., "Full-width dark sections with centered content and generous whitespace")
3. Signature elements: 3-4 reproducible CSS patterns from the site

Phase 5: Generate Output

Create the file clients/<client-name>/brand/visual-identity.md with both output formats.

Output Template

# Visual Brand Identity: [Company Name]

**Extracted from:** [URL(s)]
**Date:** [YYYY-MM-DD]

---

## Slide Preset

**Vibe:** [2-4 adjectives]

**Layout:** [1 sentence describing dominant layout pattern]

**Typography:**
- Display: `[Font Name]` ([weight, e.g., 700/800])
- Body: `[Font Name]` ([weight, e.g., 400/500])

**Colors:**

:root { --bg-primary: [hex]; --bg-secondary: [hex]; --text-primary: [hex]; --text-secondary: [hex]; --accent: [hex]; --accent-secondary: [hex]; }

**Signature Elements:**
- [Element 1, e.g., "Subtle gradient orbs as background decoration"]
- [Element 2, e.g., "Rounded cards with 12px border-radius and light shadow"]
- [Element 3, e.g., "Accent-colored left border on feature blocks"]
- [Element 4, e.g., "Grid dot pattern overlay on hero sections"]

**Font Loading:**

<link href="https://fonts.googleapis.com/css2?family=[Font1]:wght@[weights]&family=[Font2]:wght@[weights]&display=swap" rel="stylesheet">

---

## Brand Config (JSON)

For use with `content-asset-creator` and other skills:

{ "name": "[Company]", "primary_color": "[accent hex]", "secondary_color": "[accent-secondary hex]", "accent_color": "[accent hex]", "background": "[bg-primary hex]", "text_color": "[text-primary hex]", "font_heading": "[Display Font]", "font_body": "[Body Font]", "logo_url": "[if discovered, otherwise omit]" }

---

## Extraction Notes

[Any notes about the extraction — proprietary fonts that were mapped, multiple themes detected, sparse CSS from JS-rendered sites, etc.]

Font Fallback Table

When a site uses a proprietary font not available on Google Fonts or Fontshare, use this mapping to find the closest available alternative:

Decision heuristic: If unsure which category a font falls into, look at its characteristics:

• Round dots and geometric 'o' → Geometric sans
• Varies stroke widths, warm feel → Humanist sans
• Uniform strokes, neutral → Neo-grotesque
• Serifs with high contrast → Modern serif

Tailwind CSS Color Reference

If the site uses Tailwind utility classes, map them to hex values:

Grays

Slate (common for dark themes)

Blues

Greens

Common Accent Colors

Note: Tailwind classes appear as bg-blue-600, text-gray-900, border-indigo-500, etc. Strip the property prefix (bg-, text-, border-) to get the color token, then look up the hex value above.

For custom Tailwind themes (e.g., bg-brand, text-brand-light), check the page's <script> tags for a tailwind.config object that defines custom colors.

Edge Cases

JS-Rendered Sites (Sparse CSS)

Many modern sites (Next.js, React) inject styles via JavaScript. WebFetch may return minimal inline CSS. In this case:

• Focus on Tailwind utility classes in class attributes
• Check <script> tags for embedded config objects
• Look for <style> tags that contain CSS-in-JS output
• If still sparse, ask the user: "The site appears to use dynamic styling. Could you share a screenshot or provide their brand guidelines directly?"

Multiple Color Schemes (Light/Dark Mode)

Some sites define both light and dark themes via prefers-color-scheme. Extract the default (non-media-query) theme. If a dark mode variant is detected, note it in the Extraction Notes section.

Too Many Colors

Enterprise sites may use dozens of colors. Focus on:

• The hero/above-the-fold section for the primary palette
• Button/CTA colors for accent identification
• Frequency analysis — top 5-7 unique colors define the brand

No Usable Font Information

If font detection fails completely:

1. Check if the site mentions font names in its CSS comments or config
2. Look at the overall aesthetic and pick a matching pairing from the existing slide presets
3. Default to a safe, distinctive pairing based on vibe: serif display + sans body for premium; geometric sans for modern tech

Example

Running this skill on https://vapi.ai might produce:

# Visual Brand Identity: Vapi

**Extracted from:** https://vapi.ai, https://docs.vapi.ai
**Date:** 2026-02-26

---

## Slide Preset

**Vibe:** Technical, developer-focused, clean, modern

**Layout:** Dark full-width sections with centered content, card-based feature grids, generous spacing

**Typography:**
- Display: `Inter` (700/800)
- Body: `Inter` (400/500)

**Colors:**
\```css
:root {
    --bg-primary: #0F172A;
    --bg-secondary: #1E293B;
    --text-primary: #F8FAFC;
    --text-secondary: #94A3B8;
    --accent: #22C55E;
    --accent-secondary: #3B82F6;
}
\```

**Signature Elements:**
- Subtle gradient orbs in background (green-to-blue radial gradients)
- Rounded cards with slate-800 background and subtle border
- Code-style monospace accents for technical terms
- Green accent on CTAs and interactive elements

**Font Loading:**
\```html
<link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;700;800&display=swap" rel="stylesheet">
\```

*(This is an illustrative example — actual extraction results will vary based on the live site.)*

Tips

• Homepage is usually enough. If the homepage has clear branding, you don't need additional pages. Fetch a second page only if the homepage is sparse or uses a different aesthetic from the rest of the site.
• Buttons reveal the accent color. The most reliable way to identify the primary accent is to find the button/CTA background color.
• Check the favicon/logo. SVG logos often contain the exact brand colors as fill values.
• Don't over-extract. The goal is 5-7 colors, 1-2 fonts, and 3-4 signature elements. More than that creates noise, not signal.
• When in doubt, simplify. A 3-color palette (bg + text + accent) with one font family at two weights makes a clean, usable preset.

Dependencies

• Web fetch capability (for reading website pages)
• No API keys or paid tools required