There's a thread on Groddle Heights homes that discussed this very thing! However they are also in high demand. Groddle Heights have 2 light and 1 dark patch, along with veggie garden.
My old home in Groddle Meadow -- Estevan Meadow, 1300 block was it? already forget ^^;; had one dark patch, apparently leftover from early beta or something. Just sayin, apparently a rare few are out there...