|Set of tiles with base RGB of 0.2, 0.3, 0.2|
Anyway, for a current project I needed to have closely related colours on a tiled wall so I had to explore the RND function for the first time. It quickly became apparent that the way ArchiCAD generates random numbers isn't exactly random. Searched the AC-Talk forum and first thread that popped up was from as far back as 2004 - and it talked about exactly this problem. Oleg helped out with a little trick to make the numbers more random and Karl gave not just a nice explanation of pseudo-random but also a test object with what he calls the "goofy function". As usual, I learned a lot!
For whatever it's worth, what you see on the left is one of the things that can now be achieved with this object.
Edit: Zach (Zahari Dimitrov) just responded to my message and I'll be in touch with him about extending the object further.