A Power BI theme is a JSON file that sets the default colours, fonts and visual formatting of a whole report. Import it once, and every visual on every page takes on the look, instead of you formatting each chart by hand. This lesson makes one in five minutes.
Look at the live preview
Open Report Design Studio. On the right is a mock Power BI report, titled Report preview, with columns, lines, a donut, cards and a table. Everything you change shows there straight away.
Above the report, Undo and Redo step back and forward through your changes (Ctrl+Z and Ctrl+Shift+Z work too), so you can try anything. Reset brings back the report you first saw, and Undo returns your design if you pressed it by mistake.
On the left are the sections, grouped by what they do:
| Group | Sections |
|---|---|
| Colour | Palettes, Harmony, Extract, Build |
| Style | Fonts, Layout, Visuals |
| Check | A11y |
| Save | Share, Import |
Each section has a ? button in its header that walks you through its controls.
Pick a palette
Open Palettes and click one. The preview recolours at once: the first colour leads, the others follow in order for each series. Above the report, the strip of colours shows the palette in use; Copy all copies every hex code.
For a first theme, pick one from the Colour-blind-safe category, such as Okabe–Ito (CUD). These are proven, colour-blind-safe sets.
Choose light or dark
The preview has a light and a dark mode. Switch it to match the report you are making: a theme for a dark report needs different colours from one for a white page, and the studio adjusts the palette for the mode so it keeps its contrast.
Set the font
Open Fonts and click a card. The font applies to the whole report: titles, labels and tables. The list holds fonts Power BI has, like Segoe UI (the default), Arial, Calibri and Georgia, so the exported theme works on any Windows machine.
Export the theme JSON
Click Export in the bar and choose Theme JSON. Before it downloads, the studio checks the file against the rules of the Power BI theme schema. If something would make Power BI reject it, the export stops and says what is wrong, so a file that downloads is one that loads.
Import it into Power BI Desktop
In Power BI Desktop:
- Open View
- Open the Themes gallery
- Choose Browse for themes and pick the downloaded file
The report restyles straight away, and visuals you add afterwards take on the theme too.
The next lesson looks closer at choosing a palette.