Modulex was a smaller-scale-Lego-for-grown-ups, manufactured by Lego from something like 1963 and intended for use by architects and planners.
It was commercially unsuccessful but now, it seems, much-sought-after on ebay. I like the glitches brought about by the non-monospace type applied to modular blocks.
Here's some grown-ups planning something big. And the colour palette: putties, mustardy yellows, orange-reds, powder-blues. The grey with this reminds me of Belgian artist Joëlle Tuerlinckx's pH-neutral Kodak Grey tables.