How to fill colour
in any diagram or map

Click the Upload button at the top and select your image (PNG, JPG, SVG) or PDF file. You can also drag and drop the file onto the tool. On mobile, tap Upload and choose from your gallery or files.

Select any colour from the colour palette in the toolbar. Tap the + button to open the full colour picker — use the HSL sliders to create any custom colour, or type a HEX code directly. Save your custom colours to the palette for reuse.

Tap or click any enclosed bounded area on your diagram — for example, a state on a map or a cell in a diagram. That region fills instantly with your chosen colour. The tool detects the boundary lines automatically.

To change colour: select a different colour, then tap the already-filled area — it changes to the new colour. To remove a fill: select the same colour that was used to fill, then tap the area — the fill disappears.

Opacity controls how transparent the fill colour is — lower value = more see-through. Tolerance controls how strictly the tool detects boundaries — increase it if fills are leaking through slightly blurry lines.

Click PNG to download the coloured diagram as a PNG image. Click PDF to download as a PDF file. Both options preserve all your colour fills exactly as shown on screen.