Power-bi-agentic-development modifying-theme-json
Design, enforce, audit, and validate Power BI report themes. This skill MUST be invoked when a report uses the default or built-in theme, has a minimal custom theme (few or no visualStyles), or has accumulated many visual-level formatting overrides (objects/visualContainerObjects in visual.json); these are signs the theme needs attention. Also automatically invoke when the user asks to "create a theme", "design a theme", "enforce theme compliance", "audit theme adherence", "push formatting to theme", "clear visual overrides", "standardize report formatting", "update theme colors", "change theme typography", "set theme text classes", "validate a theme", "add visual-type overrides to the theme", "copy a theme", "download a theme", "apply a template", or mentions theme design, enforcement, compliance, or visual formatting inconsistency.
git clone https://github.com/data-goblin/power-bi-agentic-development
T=$(mktemp -d) && git clone --depth=1 https://github.com/data-goblin/power-bi-agentic-development "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/reports/skills/modifying-theme-json" ~/.claude/skills/data-goblin-power-bi-agentic-development-modifying-theme-json && rm -rf "$T"
plugins/reports/skills/modifying-theme-json/SKILL.mdPower BI Report Themes
Why Themes Matter
A report without a well-designed theme accumulates formatting debt. Every visual ends up with its own bespoke title size, shadow toggle, border style, and hardcoded colors in
visual.json. This creates three problems:
- Inconsistency. Visuals drift apart as authors format each one individually. One card has 14pt titles, another has 12pt; one chart has shadows, another doesn't. The report looks unfinished.
- Fragility. Rebranding or updating the visual style means touching every visual.json individually. A report with 40 visuals across 8 pages means 40 files to edit. With a theme, it's one file.
- Bloated visual JSON. Each bespoke override adds lines to visual.json, making reports harder to diff, review, and maintain. A clean visual.json should contain field bindings, position, and conditional formatting; everything else should come from the theme.
Reports using the default Power BI theme or a minimal custom theme (just
dataColors and a name) are leaving most formatting to Power BI's built-in defaults, which change between Desktop releases. A well-designed theme locks in the intended appearance.
Signs a theme needs attention:
- Many visuals have
orobjects
with redundant formattingvisualContainerObjects - Visuals of the same type look inconsistent (different title fonts, shadows on some but not others)
- The theme JSON has few or no
entriesvisualStyles - The report uses a built-in theme like "Default" or "Classic" without customization
Tooling preference: Use
CLI when available (pbir,pbir theme colors). Fall back to directpbir visuals clear-formattingmodification when unavailable. Always validate after every write.jq
Tip: Theme JSON files can be 75KB+ and 2000+ lines. Do not read the full monolithic file. Use
to split into small editable files (see Author/Modify workflow below), or usepbir theme serializeto extract only specific keys. Serialized fragments from the serialize/build workflow are small and safe to read directly.jq
For PBIR JSON mechanics (property names, filter pane selectors, ThemeDataColor syntax,
jq patterns), see the pbir-format skill (pbip plugin) -> references/theme.md.
The Formatting Hierarchy
Power BI applies visual formatting through a four-level cascade. Each level overrides the level above it:
Level 1 Power BI built-in defaults | Level 2 Theme wildcard visualStyles["*"]["*"] applies to ALL visuals | Level 3 Theme visual-type visualStyles["lineChart"]["*"] overrides wildcard for that type | Level 4 Visual instance visual.json objects + overrides everything visualContainerObjects
Core Principle
Push as much formatting as possible into levels 2 and 3. A well-designed theme means:
- Visual JSON files stay lean — no bespoke formatting noise cluttering visual.json
- Global style changes require editing one file
- New visuals automatically inherit correct defaults without manual intervention
Visual-level overrides (level 4) should exist only for true one-offs: content-specific formatting, exceptions to the visual-type default, or conditional formatting expressions.
Diagnosing Why a Visual Looks the Way It Does
When a visual renders unexpectedly, walk up the cascade:
- Check
→visual.json
andobjects
(level 4 always wins)visualContainerObjects - Check theme
for that visual type (level 3)visualStyles["<type>"]["*"] - Check theme
wildcard (level 2)visualStyles["*"]["*"] - If absent everywhere, Power BI is applying a built-in default
Workflow: Audit Theme Compliance
Use when assessing whether a report's visuals are inheriting from the theme or have accumulated stale overrides.
Step 1 — Locate the custom theme:
THEME_NAME=$(jq -r '.themeCollection.customTheme.name' Report.Report/definition/report.json) THEME="Report.Report/StaticResources/RegisteredResources/$THEME_NAME"
Step 2 — Review what the theme sets at wildcard level:
# Preferred pbir theme colors "Report.Report" pbir theme text-classes "Report.Report" # Fallback jq '.visualStyles["*"]["*"] | keys' "$THEME"
Step 3 — Continue with full audit process — see
for the complete workflow: scanning all visuals for bespoke overrides, classifying stale vs intentional vs CF, severity levels, and fix decision tree.references/theme-compliance.md
Workflow: Enforce Theme (Clear Overrides)
After applying a new theme or making significant theme changes, stale visual-level overrides prevent the new theme from rendering correctly.
With
CLI (preferred):pbir
# Clears bespoke formatting while preserving conditional formatting expressions pbir visuals clear-formatting "Report.Report/**/*.Visual" --keep-cf -f
With
(manual, per-visual):jq
# Safe: clear container chrome only (title, border, background, shadow, padding) # Does NOT touch chart-specific objects or conditional formatting jq 'del(.visual.visualContainerObjects)' visual.json > tmp && mv tmp visual.json # Aggressive: clear everything including chart-specific overrides # WARNING: also removes conditional formatting — only use if CF is confirmed absent jq 'del(.visual.objects) | del(.visual.visualContainerObjects)' visual.json > tmp && mv tmp visual.json # Always validate after jq empty visual.json
When in doubt, clear
only. LeavevisualContainerObjectsunless you have confirmed no conditional formatting exists in that visual.objects
Workflow: Author or Modify a Theme
When building or substantially revising a theme, use the serialize/build workflow via
pbir CLI. This splits the monolithic theme JSON into small, focused files that are easy to read and edit without loading 2000+ lines of JSON into context.
Serialize/Build Workflow (Recommended)
IMPORTANT: Serialize to a temporary folder outside the
directory. The PBIR validation hooks monitor.Report/for JSON changes and will flag the serialized fragments as invalid PBIR files. Use.Report/, a sibling folder, or the/tmp/flag to place the-ofolder elsewhere..Theme
Step 1 — Serialize the theme into editable files:
# From a report (outputs to a .Theme folder) pbir theme serialize "Report.Report" -o /tmp/MyTheme.Theme # From a standalone theme JSON file pbir theme serialize theme.json -o /tmp/MyTheme.Theme
This produces small, focused files:
_config.json (colors, text classes, named colors), _wildcards.json (wildcard visual styles), and one file per visual-type override (e.g., slicer.json, page.json).
Step 2 — Edit the serialized files. Each file is small enough to read and edit directly. Focus on:
—_config.json
, semantic colors,dataColors
, background/foreground variantstextClasses
— container defaults (title, border, shadow, padding)_wildcards.json- Visual-type files — overrides for specific types (textbox, image, card, etc.)
Step 3 — Build and apply back to the report:
# Build only (produces a merged theme.json) pbir theme build /tmp/MyTheme.Theme # Build and apply directly to the report pbir theme build /tmp/MyTheme.Theme -o "Report.Report" -f --clean
The
--clean flag removes the .Theme folder after building.
Quick Modifications (No Serialize Needed)
For small, targeted changes, use the CLI directly without serializing:
pbir theme set-colors "Report.Report" --good "#00B050" --bad "#FF0000" pbir theme set-text-classes "Report.Report" title --font-size 14 --font-face "Segoe UI Semibold" pbir theme set-formatting "Report.Report" "*.*.dropShadow.show" --value false
See the
skill → pbir-cli
references/modifying-theme.md for full CLI command reference.
Design Sequence
Whether using serialize/build or direct CLI commands, follow this order:
- Start from a valid base. Use a template (
), the SQLBI/Data Goblins theme, or a community template. Do not author from an emptypbir theme apply-template
.{} - Design the color system first (
, semantic colors, background/foreground variants). Color decisions cascade everywhere.dataColors - Set typography (
) — font face and size fortextClasses
,title
,header
,label
,callout
. Stick to Segoe UI / Segoe UI Semibold; custom fonts will not render on other users' machines.dataTitle - Set wildcard container defaults (
): title visibility/font/size,visualStyles["*"]["*"]
, padding, border, filter pane.dropShadow.show: false - Add visual-type overrides for types that differ from the wildcard — at minimum,
andtextbox
to suppress title/border/background/shadow.image - Validate with
, deploy, and visually verify.pbir theme validate "Report.Report"
For detailed design guidance, see
. For visual-type override patterns, see references/theme-authoring.md
.references/visual-type-overrides.md
Workflow: Promote Bespoke Formatting to Theme
When a
visual.json has formatting that should become a theme default — either for that visual type or for all visuals — promote it.
With
CLI (preferred):pbir
# Preview what would be pushed from a well-formatted visual into the theme pbir theme push-visual "Report.Report/Page.Page/Card.Visual" --dry-run # Push formatting to theme as the default for that visual type pbir theme push-visual "Report.Report/Page.Page/Card.Visual" # Push only specific components (title, background, border, etc.) pbir theme push-visual "Report.Report/Page.Page/Card.Visual" --components title,background,border
Manual process (when CLI is unavailable):
- Identify what's in
(chart-specific) andvisual.objects
(container chrome)visual.visualContainerObjects - Decide whether it belongs in the wildcard (
) or a visual-type section (["*"]["*"]
)["lineChart"]["*"] - Write the value into the theme, then validate
- Remove the override from the visual, then validate
- Verify the visual still renders correctly
Both
objects and visualContainerObjects properties map to the same visualStyles[type][state] section in the theme. The distinction in visual.json doesn't exist in the theme.
For complete property mapping tables, wildcard vs visual-type decision guide, color handling, and batch promotion across many visuals, see
.references/promoting-formatting.md
Workflow: Validate a Theme
With
CLI (preferred):pbir
# Validate a report's theme (checks JSON syntax, structure, and completeness) pbir theme validate "Report.Report" # Validate a standalone theme file pbir theme validate "theme.json" # Validate a serialized .Theme folder before building pbir theme validate "MyTheme.Theme"
Manual validation (when CLI is unavailable):
# 1. JSON syntax jq empty "$THEME" && echo "JSON valid" # 2. Required top-level keys jq '{dataColors: (.dataColors | type), visualStyles: (.visualStyles | type), textClasses: (.textClasses | type)}' "$THEME" # 3. Wildcard section jq 'if .visualStyles["*"]["*"] then "wildcard exists" else "MISSING wildcard" end' "$THEME" # 4. Valid hex colors jq '[.dataColors[] | select(test("^#[0-9A-Fa-f]{6}$") | not)]' "$THEME" # 5. No null visual-type sections jq '[.visualStyles | to_entries[] | select(.value == null) | .key]' "$THEME"
After validation, deploy and visually verify:
- Wildcard container chrome (titles, borders, shadows) applies to all visuals
- Filter pane and filter cards render correctly on all pages
- Visual-type overrides correctly suppress the wildcard for exempt types (e.g., textboxes have no title)
- Data colors cycle correctly on multi-series charts
Schema and Documentation
| Resource | URL |
|---|---|
| Official report theme JSON schema (versioned, Draft 7) | microsoft/powerbi-desktop-samples — Report Theme JSON Schema |
| Latest schema (v2.152, March 2026, exploration v5.71) — check repo for newer | reportThemeSchema-2.152.json |
Raw schema URL (for IDE integration) — update version as needed | |
| Microsoft Learn — Use report themes in Power BI Desktop | https://learn.microsoft.com/en-us/power-bi/create-reports/desktop-report-themes |
| Microsoft Learn — Report theme JSON file format | https://learn.microsoft.com/en-us/power-bi/create-reports/desktop-report-themes#report-theme-json-file-format |
| Community theme templates | deldersveld/PowerBI-ThemeTemplates |
| PBIR item schemas | microsoft/powerbi-desktop-samples — item-schemas |
IDE Integration ($schema
)
$schemaAdd a
$schema property to the theme JSON to enable autocomplete and validation in VS Code (or any JSON Schema-aware editor):
{ "$schema": "https://raw.githubusercontent.com/microsoft/powerbi-desktop-samples/main/Report%20Theme%20JSON%20Schema/reportThemeSchema-2.152.json", "name": "MyTheme", "dataColors": ["#1971c2", ...] }
The schema is used verbatim by Power BI Desktop to validate themes on import — if the JSON fails schema validation, Power BI Desktop will reject the theme. Always target the schema version that matches the Power BI Desktop version in use. Schemas follow the pattern
reportThemeSchema-2.{version}.json where the version matches the monthly Desktop release.
Theme Top-Level Keys
| Key | Type | Purpose |
|---|---|---|
| string | Display name shown in Power BI UI |
| string[] | Ordered hex palette for data series |
/ / | string | Flat hex keys for CF measure semantic colors |
/ / | string | Gradient color extremes (flat hex keys) |
variants | string | , , , , etc. |
variants | string | , , , |
| object | Typography per semantic role (, , , , , etc.) |
| object | formatting cascade |
References
— Color system design, typography, wildcard minimum set, schema integrationreferences/theme-authoring.md
— Serialize/build workflow: splitting themes into editable files, editing, rebuilding, validation, temporary folder guidancereferences/serialize-build.md
— Applying templates, post-apply enforcement, clearing visual overrides, normalizing hardcoded colorsreferences/applying-themes.md
— Copying themes between reports, extracting/downloading themes, comparing themes, consolidating across a portfolioreferences/copying-themes.md
— Promoting bespoke visual.json formatting to theme: push-visual CLI, objects vs visualContainerObjects, wildcard vs visual-type, property mapping tablesreferences/promoting-formatting.md
— Systematic audit workflow, stale override classification, severity levels, fix decision treereferences/theme-compliance.md
— Override patterns for textbox, image, shape, card, kpi, slicer, lineChart, barChart, tableEx, and matrixreferences/visual-type-overrides.md
Related Skills
→pbir-cli
— Full CLI command reference for theme operations (serialize/build, set-colors, set-text-classes, set-formatting, push-visual, fonts, background, icons, diff)references/modifying-theme.md
→pbir-cli
— Applying templates, copying themes between reports, clearing visual overridesreferences/apply-theme.md
(pbip plugin) — Full theme mechanics: ThemeDataColor syntax, filter pane selectors, jq modification patterns, clearing overridespbir-format
— Report design principles: 3-30-300 rule, layout, spacing, color usage, accessibilitypbi-report-design