Colour
Colour, the most subjective of the tests mostly because it’s purely about our preferred aesthetics and our ability to perceive certain colours. Some prefer vibrant images while others prefer more muted colours. For me, this was pretty difficult but my favourite is the Galaxy S9 because it’s vibrant but not oversaturated, leading to an image that’s very pleasing overall.
The Galaxy S8 is a close second with the iPhone X and Mate 10 Pro trailing in third and fourth.