Guy Berryman

Throughout the video the Prophet 6 is shown and at the 3:20 mark Chris Martin says Guy is the band member who programs the synths.

At 3:04 and 3:19 of this video, Guy can be seen playing a Prolight Laser Harp.

Person who uploaded this video actually played Berryman's RMI Harmonic Synthesizer. This very synth came to the person for servicing, but he also took a video of playing the very synth. The person confirms this in the comments' section.

The Juno 6 is shown throughout this video and at the 3:20 mark of the video Chris Martin says Guy Berryman programs the bands synths

The Yamaha CS-80 is shown throughout the video on the right side beside the tree in Coldplay's studio "The Bakery" and at the 3:20 mark Chris Martin says Guy Berryman programs the bands synths

Used on "Hymn for the Weekend", as mentioned by A Head Full of Dreams co-producer Rik Simpson in this March 2016 Sound on Sound interview.

"The ‘KEGuyEndProphet’ track is a Prophet 12 played by Guy [Berryman] and it has an EastWest Quantum Leap Spaces reverb on it, which is one of my favourites."

Throughout this performance of “Speed of Sound”, we see Guy playing a Moog Minimoog Voyager Performer. This synth has been with Guy since at least 2004 and made appearances as recently as Coldplay’s 2014 Ghost Stories tour. The synth can be seen particularly well from around 0:18 to 0:25