julianobarbosa/power-bi-themes

Power BI Themes Skill

Manage report-wide themes and per-visual conditional formatting. No Power BI Desktop connection is needed.

Applying a Theme

Power BI themes are JSON files that define colours, fonts, and visual defaults for the entire report. Apply one with:

pbi report set-theme --file corporate-theme.json

This copies the theme file into the report's StaticResources/RegisteredResources/ folder and updates report.json to reference it. The theme takes effect when the report is opened in Power BI Desktop.

Inspecting the Current Theme

pbi report get-theme

Returns:

• base_theme -- the built-in theme name (e.g. "CY24SU06")
• custom_theme -- custom theme name if one is applied (or null)
• theme_data -- full JSON of the custom theme file (if it exists)

Comparing Themes

Before applying a new theme, preview what would change:

pbi report diff-theme --file proposed-theme.json

Returns:

• current / proposed -- display names
• added -- keys in proposed but not current
• removed -- keys in current but not proposed
• changed -- keys present in both but with different values

This helps catch unintended colour changes before committing.

Theme JSON Structure

A Power BI theme JSON file typically contains:

{
  "name": "Corporate Brand",
  "dataColors": ["#0078D4", "#00BCF2", "#FFB900", "#D83B01", "#8661C5", "#00B294"],
  "background": "#FFFFFF",
  "foreground": "#252423",
  "tableAccent": "#0078D4",
  "visualStyles": { ... }
}

Key sections:

• dataColors -- palette for data series (6-12 colours recommended)
• background / foreground -- page and text defaults
• tableAccent -- header colour for tables and matrices
• visualStyles -- per-visual-type overrides (font sizes, padding, etc.)

See Microsoft theme documentation for the full schema.

Conditional Formatting

Apply data-driven formatting to individual visuals:

# Gradient background (colour scale from min to max)
pbi format background-gradient visual_abc --page page1 \
    --table Sales --column Revenue \
    --min-color "#FFFFFF" --max-color "#0078D4"

# Rules-based background (specific value triggers a colour)
pbi format background-conditional visual_abc --page page1 \
    --table Sales --column Status --value "Critical" --color "#FF0000"

# Measure-driven background (a DAX measure returns the colour)
pbi format background-measure visual_abc --page page1 \
    --table Sales --measure "Status Color"

# Inspect current formatting rules
pbi format get visual_abc --page page1

# Clear all formatting rules on a visual
pbi format clear visual_abc --page page1

Workflow: Brand a Report

# 1. Create the theme file
cat > brand-theme.json << 'EOF'
{
  "name": "Acme Corp",
  "dataColors": ["#1B365D", "#5B8DB8", "#E87722", "#00A3E0", "#6D2077", "#43B02A"],
  "background": "#F8F8F8",
  "foreground": "#1B365D",
  "tableAccent": "#1B365D"
}
EOF

# 2. Preview the diff against the current theme
pbi report diff-theme --file brand-theme.json

# 3. Apply it
pbi report set-theme --file brand-theme.json

# 4. Verify
pbi report get-theme

JSON Output

pbi --json report get-theme
pbi --json report diff-theme --file proposed.json
pbi --json format get vis1 --page p1

---

Gotchas

• Theme JSON keys are case-sensitive and partially undocumented: One wrong key in dataColors or visualStyles is silently ignored — no error, the theme just falls back to default for that property. Diff against a known-good theme JSON before troubleshooting "theme not applying".
• dataColors array order maps to series ordinal, not to series name: Renaming a series or changing legend order rotates the colors. Lock brand colors per-series via measure-level color rules in visualStyles, not via array position.
• set-theme --file copies the file at command time: Later edits to the source corporate-theme.json don't propagate to the report — you must re-run set-theme. CI pipelines must re-apply the theme on every build for the latest version to land.
• diff-theme does not catch missing-key regressions: Removing a key from the proposed theme appears under removed but Power BI's runtime treats removal as "fall back to default" — visually this looks like a theme bug, not a missing-key bug.
• Conditional formatting via format background-measure requires the color measure to return a valid hex string or named color: Returning a number or blank produces "no formatting applied" with no error. Wrap the measure's return in IFERROR(..., "#FFFFFF") to fail safely.
• format clear removes ALL formatting rules on a visual, not just background: Font, data-label, and conditional title rules go too. The CLI does not currently support selective rule deletion — clear and re-add is the only workflow.