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.
Use TikZ/PGF to programmatically draw spacetime diagrams for uniformly accelerated observers. Set the acceleration, initial conditions, and other parameters.
Questions/Comments to Robert McNees at email@example.com, http://jacobi.luc.edu January 2015
This example from section three of the LaTeX verse package documentation demonstrates an ambitious use of \indentpattern to create a striking visual effect. In this case it is defined to recreate the famous typesetting of the original Mouse's Tale as it appeared in print.
Background: "The Mouse's Tale" is a poem by Lewis Carroll involving a 'quadruple pun' which appears in his novel Alice's Adventures in Wonderland. It uses typesetting style to create the final pun (it is a mouse's tale typeset in the shape of a mouse's tail).
For more details see the poem's Wikipedia entry.