I've been watching where flowers and mountains have been showing up in SPN episodes this season. There were a bunch more in 7.12. I put the caps here so I could find them later.
Reds and yellows were used heavily in this episode for the time spent in 1944 and for things associated with Kronos. Often SPN has red, yellow or orange flowers when there is peril or something just isn't right. Because of the amount of red and yellow used in this episode, it's a little harder to see a pattern but it seems to still hold in this case.
Witness number one was a real trip and he got his own small red flower.
Kronos's house had subtle wallpaper that might have flowers and there are pink enameled roses on the front of the fireplace. One of the mountain landscapes is on the wall here.
Lila Taylor's house had another mountain landscape and she's trapped between her clock (time) and floral wallpaper and dress.
Lila in the present (physically) with a flowered blouse.
Mountains paintings have been showing up a lot this season also. I don't know if it's intentional or because a good percentage of landscape pictures include mountains. Most of the paintings in this episode were mountains.
House where Dean left the letter for Sam.