When using True Tone on new 16" MBP, blue shadow/anti aliasing is displayed around things rendered on screen (both native retina display and external displays). This only occurs when using "scaled" resolution above the default.

Apple discussion thread: https://discussions.apple.com/thread/250963040

For those without AppleID: https://superuser.com/questions/1511128/16-macbook-pro-blue-pixel-aliasing-on-external-display