So you want to customize your navigation bar to make it look like the Google Pixel's navigation bar. But, you find a lot of articles that show you how to get the Pixel's navigation bar but turns out that all of the processes mentioned require root access. Well, here's a guide to getting the Google Pixel's navigation bar in a minute without rooting your Android.
First 30 seconds: Go to the Play Store and install this application called Pixbar.
Next 30 seconds: Open the application and tweak the spacing to correctly fit into your current navigation bar. Now click apply. That's it.