Paul & Joe Lesable sweater
Q (Ben Whishaw) wears a Paul & Joe sweater with the Billy Reid jacket outfit in SPECTRE.
The lightweight sweater has a red and blue multicolor pattern, round collar, long sleeves, no appliqués. The model name is Lesable, color code 31 (blue).
The sweater is worn towards the end of the film in the London scenes, together with the Billy Reid Astor coat.
Thanks to SherlockHolmes for the ID.