Saturation. The Sony A7R III's mean default color saturation is 112.2% at base ISO or in other words, oversaturated by 12.2%. That's fairly typical these days, just a touch higher than average.
Below are crops from our laboratory Still Life target comparing the Sony A7R Mark III's JPEG image quality to its predecessor, the A7R Mark II, as well as to its A-mount sibling, the Sony A99 Mark II.