You can try this app, it can replace the AOD and display a notification ring around the front camera or the whole screen.Do pixel phones not have the little LED notification light thingy? I don't know if it was a Oneplus thing or what but god damn I miss it. Used to be different colours depending what was there so i knew to open my phone or not.
Notification light for Pixel - Apps on Google Play
aodNotify - Notification light / LED for Pixel!
play.google.com
But if you want colors you'll need to pay for pro.
I tried it and it works well, but in the end I removed it, I don't want my phone to blink and call for engagement, I'll check for notifications myself, I just need to either move it slightly or tap the screen for it to show notifications.