Despite setting the layer or the symbology of the features to semi-transparent, when performing a selection, the features become solid. I want to edit those features based on properties of the features/background image below them.

How can I set a transparency when features are selected?

2 Answers 2


Make selection color transparent by reducing opacity in Set Selection Color window.

Settings menu > Options > Canvas & Legend > Selection color

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The same setting is available on a project-specific basis in the Project > Properties menu. You may need to restart QGIS to see the changes.

Here are another few options for making the background visible behind selected features:

Use an outline symbol type:

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You can pair this with centroid fill:

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Or add multiple, offset outlines for a more filled polygon appearance. The example image below has 6 symbol layers with offsets of 0, 1.5, 3, 4.5, 6, and 7.5 mm.

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  • Brilliant workarounds! I also managed to get it to be semi-transparent by changing the colour properties themselves under … choose colour... opacity. Commented Jul 4, 2018 at 2:30
  • 1
    Nice! I didn't think to look for transparency in the color selection window. I'll edit my answer to include that info.
    – csk
    Commented Jul 4, 2018 at 16:50
  • I have tried this many times, reducing opacity down to c. 5%, but it doesn't seem to make any difference. Is there anything else I need to change? I am currently on 3.6.3 Noosa
    – JimS-W
    Commented Sep 4, 2020 at 9:24
  • @JimS-W Did you restart QGIS after changing the transparency setting?
    – csk
    Commented Sep 5, 2020 at 14:31
  • 2
    I was having the same issue, @JimS-W - got to Project Properties (Ctrl + Shift + P) and then General. You'll see there where you can change the selection color / transparency. I don't know why the above solution didn't work for me, but I had to change it in the project properties instead of Settings.
    – Will
    Commented May 6, 2022 at 18:00

In QGIS 3.10.9, this might not work. Using this path (Settings > Options > Canvas & Legend > Default Map Appearance) to change colors/transparency of selected features will be overridden by the project properties. I successfully changed color and transparency of selected features by going to Project > Properties > General > Selection Color and making my changes there.

  • Saved me a lot of time! Commented May 19 at 19:06

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