Google starts rolling out Android Wear 2.8, here's what's new
Before going into details, it's worth noting that this is an update on the Android Wear app on the smartphone, so it's not the same as the OTA update on smartwatches. Also, keep in mind that the roll-out is going to take a few days to reach all phones.
Now, Android Wear 2.8 is supposed to improve notification glanceability with a new layout that shows more of the messages you receive at a glance. Finally, the changelog mentions that Google has made the background darker to allow for better readability.
There might be other changes included in the app's update, but these are the only ones confirmed by Google. You can see what the new dark background looks like in the picture above.