No amount of changing the color adjustment will fix the white balance. I feel I need to address a few things:
1) I think the V20 is a great phone, but the display is not accurate.
2) It has nothing to do with AMOLED vs LCD. It has to do with color accuracy. I came from Samsung, but I used Basic Mode (the most color accurate mode). It's not "over saturated" or "punchy". It's accurate. My other devices are a Pixel C, iPad Pro 12.9, Nexus 6p (being replaced with a Pixel), an Acer 4K PC monitor, and an Acer Predator PC monitor. I have calibrated both PC monitors with an Xrite colorimeter.
3) Every other display I use is calibrated, so the V20 NOT being calibrated stood out more than I thought it would.
4) I'm not trying to convince anyone to not enjoy the phone. I know plenty of people will, but I see some people around here saying things like "you can fix the display". Well, plain and simple, no you can't. You need to decide if you're ok with a display that can't display accurate colors. The vast majority of people probably will be. Will LG release an OTA to "fix" this? Possibly, but they have not done that historically. I held out a sliver of hope that they would have an sRGB mode in Dev Options like the Nexus 6p but they don't.
I didn't post to try and change anybody's mind. I hope everyone gets the phone they want and enjoys it. The display is/was (for me), the only real negative I found with the device.