In this post I will show you how to create the image below using Blender:
0. First, I recommend to split your viewport in two to tweak the materials and preview the result at the same time, like so:
1. Now change the shading mode to Rendered (Press Z to open the pie menu and select Rendered);
2. Add a new material to your mesh. I used the default cube in this example;
3. Our main shader is an emission node, so add one into material output. You can tweak the Strength value later;
4. To create the grayscale pattern, we need to combine two grayscale textures: a Musgrave and a Voronoi node. To do this, plug the musgrave color output into Voronoi vector input and adjust the scale until you find a good result.
5. Add a Color Ramp node to control the number of rings in the texture. We're basically removing the gap between black ( = 0) and white (= 1).
6. Now change the default color to something you like. You can also add more than two colors:
7. Plug this color ramp to the emission node and that's it!
To create an interesting image, enable the bloom effect and play with the values. This is my setup: