There's a different colored block in every map, in Slate, it's golden, in Bedroom, it's platinum, in Kitchen, it's diamond, in Construct, it's black, and in the dark versions of maps, it's the same as the light version. I forgot the other ones, but they are hidden around, and every map created has it's own "Golden Block" of a different color/texture, it's generated when the map is created. It's not always golden.