Example Venn Diagram with isolated areas filled
This example helps to show how the isolated areas of a Venn diagram can be filled / coloured.
It was created as part of this answer on TeX StackExchange.
Other options for creating Venn diagrams with multiple areas shaded can be found in the Overleaf gallery via the Venn Diagrams tag.
Venn diagram with PGF 3.0 blend mode
With TikZ 3.0, there’s a new kind of transparency: you can use blend modes.
This short Venn diagram example shows how the screen blend mode can be used to create a clear visual effect with just a few lines of code.
Overall, there are 16 blend modes to choose from: normal, multiply, screen, overlay, darken, lighten, color dodge, color burn, hard light, soft light, difference, exclusion, hue, saturation, color, luminosity.
The code for this example was written by Paul Gaborit, published on TeX.SE and then on TeXample.net. This abstract is adapted from that on TeXample.
Paul Gaborit (via TeXample.net)