Theme & Branding

Apply a professional theme to a generated PBIP project. This skill swaps the default CY25SU11 theme for a chosen theme (preset or custom), updates report.json to reference it, and optionally applies logo / corporate color palette overrides.

This skill follows Microsoft's official report-theme techniques:

• Use report themes in Power BI
• Create custom report themes in Power BI Desktop

See references/theme-schema.md for the full canonical reference.

When to Use This Skill

• After query-to-pbip has produced a PBIP and before bi-dash-creator composes the dashboard
• The user requests a specific look ("corporate", "modern", "minimal", "dark", or a brand)
• A custom theme JSON file is supplied
• A logo or color palette needs to be embedded

Inputs

• PBIP project path — <ProjectName>/ directory produced by query-to-pbip
• Theme selector — One of: corporate | modern | minimal | dark | custom
• Custom theme path (optional) — Required when theme = custom; path to a Power BI theme JSON file
• Logo path (optional) — PNG/SVG file to embed as a top-of-page image
• Color overrides (optional) — { primary: "#hex", secondary: "#hex", accent: "#hex" }

Built-in Theme Presets

Preset theme JSONs live in assets/themes/. Each preset declares the $schema URL, a full 8-color dataColors palette, all five structural colors (background, secondaryBackground, foreground, secondaryForeground, tableAccent), the four sentiment/diverging slots, the ten core textClasses, and baseline visualStyles for *, page, and cardVisual.

Theme Anatomy (the four authoring surfaces)

A Power BI theme has four layered surfaces. Author each in order; later surfaces override earlier ones.

1. Theme colors — the data palette

• dataColors[] — the rotating palette for dynamic series. Provide ≥ 8 entries.
• good / neutral / bad — KPI sentiment + waterfall increase/decrease/total + conditional formatting sentiment.
• maximum / center / minimum / null — endpoints for diverging color scales (gradient conditional formatting on tables/matrices).

Dynamic vs. static series: dynamic series (one color per category) are auto-themed. Static series whose color was explicitly picked in the format pane are locked and not overridden by a theme swap. Account for this when planning visual brand consistency.

2. Structural colors — the chrome palette

Five named slots drive non-data colors across page, gridlines, axes, and tables:

• background, secondaryBackground
• foreground, secondaryForeground
• tableAccent

3. textClasses — typography defaults

Ten text classes cover every label in a Power BI visual: callout, title, header, label, largeLabel, smallLabel, semiboldLabel, boldLabel, largeLightLabel, lightLabel. Each takes fontFace, fontSize (points, 6–72), and color.

4. visualStyles — per-card overrides

Three-level keyed object: visualStyles.<visualType>.<styleName>.<cardName>.

• <visualType> — * (default) or a specific name (columnChart, lineChart, cardVisual, tableEx, pivotTable, slicer, page, etc.).
• <styleName> — * (default style) or a named style preset (see below).
• <cardName> — formatting card (background, border, title, labels, legend, dataPoint, valueAxis, categoryAxis, outspace, etc.).

Colors inside visualStyles must be wrapped as { "solid": { "color": "#hex" } } — unlike the bare hex strings in theme/structural colors.

Binding to the palette via ThemeDataColor

Inside visualStyles, prefer palette references over hard-coded hex so the visual recolors automatically if the palette changes:

"color": { "solid": { "color": { "expr": { "ThemeDataColor": { "ColorId": 0, "Percent": 0 } } } } }

ColorId is the zero-based index into dataColors; Percent is a tint (positive) or shade (negative).

Style presets (multiple looks per visual type)

A single theme can ship multiple named looks (e.g., Hero vs Mini card styles). Users select presets in the format pane. Define them under visualStyles.<visualType>.<StyleName>:

"cardVisual": {
  "*":    { /* default */ },
  "Hero": { "labels": [{ "fontSize": 48 }] },
  "Mini": { "labels": [{ "fontSize": 18 }] }
}

$schema declaration

Every preset and custom theme should reference the official schema for editor IntelliSense + validation:

"$schema": "https://raw.githubusercontent.com/microsoft/powerbi-desktop-samples/main/Report%20Theme%20JSON%20Schema/reportThemeSchema-2.140.json"

Finding Visual Property Names

From Microsoft's Find visual properties, use one of:

1. $schema autocomplete in VS Code / a JSON editor
2. Format pane in Power BI Desktop — card names match cardName, property labels match property keys after camelCasing
3. PBIR files — inspect <Project>.Report/definition/pages/<page>/visuals/<visual>/visual.json objects section; the keys you see (background, title, labels, …) are exactly the cardName values needed in visualStyles

Workflow

Step 1: Locate the PBIP

Find <ProjectName>.Report/StaticResources/SharedResources/BaseThemes/ inside the project directory. This is where the active theme JSON lives.

Step 2: Select the Theme File

• If theme = corporate | modern | minimal | dark → copy assets/themes/<theme>.json into the BaseThemes directory
• If theme = custom → copy the user-supplied theme JSON into the BaseThemes directory (validate it first against references/theme-schema.md §10 — Validation Rules)
• If theme is omitted or unknown → keep the default CY25SU11.json

Step 3: Apply Color & Branding Overrides (Optional)

When the user supplies brand overrides, patch the theme JSON in this order so all surfaces stay consistent:

1. dataColors[0..2] — set primary / secondary / accent if provided.
2. tableAccent — mirror primary so tables get the brand accent.
3. title text class color — use primary for visual titles.
4. good / bad — leave defaults unless the user supplies sentiment overrides (the default green/red are accessibility-tuned).
5. visualStyles.cardVisual.*.labels[0].color — if the card big-number color is hard-coded in the preset, swap to primary. Prefer rewriting it as a ThemeDataColor expression (ColorId: 0) so future palette swaps cascade automatically.

Preserve all other theme properties (including $schema, textClasses, structural slots not being changed, and existing visualStyles cards).

Step 4: Update report.json

In <ProjectName>.Report/definition/report.json, update the themeCollection.baseTheme.name to match the new theme's name property. Update resourcePackages[].items[] to point at the new theme file path:

"resourcePackages": [
  {
    "name": "SharedResources",
    "type": "SharedResources",
    "items": [
      {
        "name": "<themeName>",
        "path": "BaseThemes/<themeName>.json",
        "type": "BaseTheme"
      }
    ]
  }
]

Step 5: Embed Logo (Optional)

If a logo path was supplied:

1. Copy the image into <ProjectName>.Report/StaticResources/RegisteredResources/<sanitized-name>.<ext>
2. Register it in report.json under resourcePackages[] with type: "RegisteredResources"
3. On page 1, add a new image visual at the top of the page (suggested position: x: 20, y: 10, w: 200, h: 60). The image visual references the registered resource by name.

Step 6: Validate (per Microsoft schema)

After modifications, verify:

1. Theme JSON parses as valid JSON.
2. name is present and matches the file basename and the themeCollection.baseTheme.name in report.json.
3. dataColors has ≥ 8 entries; each is a 6-digit hex.
4. All structural color slots (background, secondaryBackground, foreground, secondaryForeground, tableAccent) and sentiment/diverging slots are valid hex when present.
5. All textClasses[*].fontSize values are integers in [6, 72]; all textClasses[*].color values are valid hex.
6. Colors inside visualStyles are wrapped as { "solid": { "color": "#hex" } } (or ThemeDataColor expressions) — never bare hex strings.
7. resourcePackages[].items[].path files all exist on disk.
8. The default CY25SU11 theme entry is not removed if it's still referenced anywhere.

Step 7: Re-zip (Optional)

If the project was previously zipped, re-run query-to-pbip/scripts/package_pbip.py to refresh the archive.

Resources

• assets/themes/corporate.json — Corporate preset theme
• assets/themes/modern.json — Modern preset theme
• assets/themes/minimal.json — Minimal preset theme
• assets/themes/dark.json — Dark preset theme
• scripts/apply_theme.py — End-to-end theme application script (copy theme, patch report.json, validate)
• references/theme-schema.md — Power BI theme JSON schema reference and validation rules

Error Handling

Considerations & Limitations (from Microsoft docs)

• Locked properties: once a user explicitly picks a color or font in the format pane on a static series, the theme no longer overrides it.
• Non-themable properties: a small set of properties (mostly tied to data binding and certain legacy visuals) cannot be themed at all.
• Custom AppSource visuals may ignore themes or honor only a subset.
• No version field: theme JSON is implicitly versioned by the $schema URL date suffix.