Probably because they're being displayed wrong. If you tell an sRGB to display red 100%, it does, if you tell a wide gamut monitor to do that, it's oversaturated (or "more vivid"), unless everything else is set up correctly :)
Hence you'd have to calibrate both to make it fair. The settings on both will be completely different from each other. It would be very easy to make the Philips look amazing, and the LG look crap ;)
Try one of these, see if you can set some sort of custom resolution: http://www.everymac.com/systems/apple/macbook_pro/macbook-pro-retina-display-faq/macbook-pro-retina-display-hack-to-run-native-resolution.html