I have noticed the new version of Android has notification dots.
The new multicolor dots I find frustrating. I would prefer if I could set one color for all notification dots(like red for example).
....we even extract the color of the dot from your icon.
So, not possible
In complement to what beeshyams reply:
As of now, you can't change Oreo Notification dots colors in AOSP, starting from Android 8.0, native Notification Dot color depends on its app icon colors.
I said AOSP, because some mobile manufactures are using their own UI apps (Launcher/ Theme apps etc... ), thus they can control Notification dots like Nova Launcher.
This example is using Numeric Badges, you can change the Numeric Badges to None, Dynamic Badges or Dots as seen in Android O.