I snapped up a quick pic of the R. acicularis x R-15 seedling. The fall foliage is very autumn-esque.
Here in zone 5 northern Ohio my plants of (R. acicularis x R-15) have already lost their leaves. Interestingly, my plants of R. acicularis still have their leaves.
I thought it was interesting that the colors were more vivid that the similary aged and near by Rosa virginiana. R. virginiana is stated in many texts as being very vivid. Your hybrid, however, has a more rustic look to it. I like both reguardless 8)