The Aztec Underworld was a vast veritable labyrinth of layers and levels which needed looking after by multitudes of ghastly Gods. Most of them with unpronounceable and unspellable names.
Gods of the Underworld were usually depicted in garish color in two-dimensional form. Three dimensional Gods with those colors would be a bit over the top. But MICTLAN itself is a gloomy, dank and depressing place, full of worms and creepy-crawlies.