When it comes to Android's UI design, this includes the Google apps, Google tends to alter things here and there, sometimes being big changes and other times making small subtle shifts in design that only slightly change the way an app looks. With Android 5.0 Lollipop, there was an obvious huge shift in the way the operating system as a whole looked when compared to the previous(for some, still current)Android 4.4 Kit Kat. The same thing goes for apps, although maybe a little less so with the UI than of the OS itself. Coming up in Android 5.1, it seems Google will be applying some of these very subtle changes and alterations to the Contacts application, but not to the whole app, rather just the edit and create contact screens.
In these screenshots taken by Android Police, you can see some of the minor alterations in UI design that Google is bringing to the contacts app in the upcoming Android 5.1. Perhaps it's just my eyes, but the colors in the 5.1 version of the app for the header look a little more bright and vibrant of a blue(a slightly lighter hue)in contrast to the Android 5.0 version. The popup panel for categorizing contacts(I.E. friends, family, work, etc.)has been changed up and slimmed down a bit too. The panel will no longer be as wide as the current panel when adding a contact to a specific category in the Android 5.0 version of Lollipop.
It seems that Google will also be adding in a trash can icon just to the left of the three dots button in the top right corner, which will give users the ability to simply delete a contact off of their device when inside the edit contact screen. As noted by Android Police, these changes are seemingly just for the edit contact screen and contact creation screen, so Google is more or less bringing that section of the contacts app forward to the same design as the rest of the app. There's still no word when Google will be releasing Android 5.1 but we imagine it won't matter to some users seeing as how many people are still waiting on their carriers to push out compatible versions of Android 5.0.