My display remains greenish all the time

@srtechente59078 At this point the most obvious solution for you is to replace your screen. Since both the LCD and the digitizer are contained in the display assembly, replacing it should solve all of the problems you're seeing.

The good news is your prompt action with getting the phone cleaned probably saved it, but displays are notoriously sensitive to liquid damage.

Replacing the screen is something you can do yourself, but if you're not comfortable then you'll want to take it to a service center to have the repair done. Here's the iFixit guide that will take you through the procedure step by step.

Motorola Moto G4 Plus LCD Screen and Digitizer Assembly Replacement - iFixit Repair Guide

You can buy a replacement screen right here on iFixit or go shopping yourself on places like Amazon, eBay and AliExpress.

Moto G4 Plus Screen: LCD Display + Digitizer Replacement Kit - iFixit

If you don't have the tools already, I'd recommend the Fix Kit version. For an extra $6 USD you will get all the tools needed to open up the phone, remove all the internals and replace them into a new display, along with all the adhesives needed to put the phone back together again.