It's a delicious irony that Shakespeare is celebrated at this most English of opera festivals by a Frenchman directing a French comedy. Britten's A Midsummer Night's Dream follows in August, but before that Glyndebourne Festival Opera serves up Laurent Pelly's typically quirky take on Berlioz's Béatrice et Bénédict, itself an oblique tribute to The Bard, taking the “merry war” between Beatrice and Benedick from Much Ado About Nothing as his wafer thin plot. It's light and fluffy, making it perfect summer festival fare. Sadly, like a soggy soufflé, Pelly's one-trick staging soon falls flat.

Crowds rejoice as the victorious Don Pedro of Aragon returns to Sicily from the Moorish wars. Three giant boxes flip open their lids to reveal the flag-waving chorus. Messina is a toy-town of boxes in Barbara de Limburg's set designs, sometimes stacked precariously on top of each other, wheeled about the stage. Characters pop in and out of flaps in the sides. Master of Music Somorone and his entire choir clamber from the depths of just a single box. Preparations for the wedding of Héro and Claudio feature a pair of flunkies delivering a sequence of boxes which get increasingly smaller. Pelly keeps the sight gags coming, but they're essentially the same joke.

Berlioz's music isn't as riotous and flooded with Mediterranean hues as Benvenuto Cellini, but there is plenty of colour in the score. None of it is reflected in Pelly's production. Monochrome costumes and sets are many shades of grey. Grey clouds scud across a grey sky. “Nuit paisible et sereine!” the gorgeous moonlit reverie for Héro and her maid, Ursule, lacks any lunar magic, the moonlight replaced by electric bulbs lining a giant box containing Hero's bridal gown. Even the flags are drained of colour. Etna apart, is Sicily really so ashen?

In Berlioz's opera, it's the dialogue that advances the plot. The skirmish of wits between Hero's cousin, Béatrice, and returning soldier Bénédict is deftly directed, aided by lively performances from Stéphanie d'Oustrac and Paul Appleby, she flinging the insults with French disdain, he protesting too much in his resolve to die a bachelor. Bénédict is tricked into believing that Béatrice's mockery and insults are a phoney war and that she secretly loves him. Héro and Ursule play the same trick on Béatrice, resulting in a clumsy amorous encounter and an eventual marriage – out of pity for each other, of course – after which they declare, truce signed today, they'll return to being enemies tomorrow. In her Act II aria, agitated at coming to terms with the idea that Bénédict actually loves her, d'Oustrac was in fine voice, her wiry mezzo giving full vent to Béatrice's conflicting emotions as she abandons herself to the idea of love. Appleby's compact tenor wasn't always ideally free at the top, but his aria “Ah! Je vais l'aimer”, in which he quickly falls for the bait and declares he will pursue Béatrice, was charmingly done.

Replacing Hélène Guilmette as Héro, Sophie Karthäuser took a little time to hit her stride, her top notes – like Pelly's production – lacking colour. However, by the time of her moonlit duet with Katarina Bradić's plushly-toned Ursule, her singing was more secure, the two voices blending beautifully. Philippe Sly's elegant bass-baritone made for an attractive Claudio, while Lionel Lhote had tremendous fun as Somarone, an additional character introduced by Berlioz to parody 'high art', even if his antics means he rather outstays his welcome. The Glyndebourne Chorus performed nobly whilst being given silly things to do.

"A caprice written with the point of a needle" was how Berlioz described his opera. That filigree detail was ever present in the pit, Antonello Manacorda drawing nuanced playing from the London Philharmonic Orchestra. Woodwinds chuckled in the overture – a tad carefully paced – while the flute and clarinet postlude to Act I rippled like watered silk. Here was all the colour bleached from Pelly's staging.