I've always thought the Wild Gumdrop flower set from Backyard Stuff was a bit too cutesy-coloured for my personal taste. So, I finally decided to do some recolours based on the Autumn season. Whether or not you like the originals, these recolours add extra variety to the game's outdoor decor 
In another post, I have a default replacement set which includes these colours as well, so you don't need both. It just depends on whether you want these Fall colours in addition to the originals, or the default replacements. You don't need both packages, but they are compatible if you happen to install both.
There are 2 colours of leaves, with 11 colours of flower combinations for each.
They are found in game under flowers by the name Fall Flowers by Simmiller, at a reduced cost of 35 Simoleons per plant. You'll notice in the information section they have an environment score of +1, and an eco footprint value of +2. This is from the original plant and was not changed because why not, amiright?!! I took off the 'can be struck by lightning' tag, and added in some venues so you'll possibly see the plants decorating these areas: Arts Center, Park (forest), Park, Ruins, and Arts Commons.
Have fun decorating your landscapes!