Shen Wei, Barbican Theatre, LondonRomeo and Juliet, Royal Opera House, London

Human paintbrushes daubed the Barbican stage, while at Covent Garden, an injured first-night Romeo gave a humble soloist his chance to dazzle

Sometimes, more often than even the biggest dance fan is ready to admit, committing to an evening of contemporary dance is an act of faith. When the dour-faced, drab-clad dancers of Shen Wei's company first appeared, one by one, on a blank white Barbican stage, one could only trust that Dance Umbrella knew something we didn't.

What you couldn't guess from the opening minutes of Connect Transfer, the choreographer's latest work, was how it would gradually colour up, both actually and metaphorically, to a point resembling an explosion in a Dulux factory. Too bad that photographers were invited only to view the dull first 10 minutes from the stalls, rather than shin to the lighting rig for a proper eyeful. For this was dance as literal body-writing, scrawled upon the floor: the body as Magic Marker, in a range of vibrant colours. But first, we had to sit through a session of what could best be described as extreme yoga. Each dancer advances into the big white space, arranges themselves in a mangled knot, and holds it rigid while other bodies file on and assumeimpossible poses to lock limbs with them, in increasingly odd formulations.

Things only hot up when a woman appears wearing paint-soaked mittens, flings herself to the floor and proceeds to jack-knife at the speed of a terrified worm attempting to foil a hungry beak. Her hands, meanwhile – miraculously, it seemed to me – move only in smooth circular sweeps, imprinting the floor with a startlingly elegant copperplate. The initial effect, as when blood spurts from an accidental cut – is both liberating and rather shocking.

The Chinese-born New Yorker has a stock of such ideas, and is adept at controlling their flow. At one point, roughly midway through the 70 minutes, he flips into a different world entirely: perpendicular, cartoonish and fast, feet comically facing one way and hips the other, figures bobbing up and down like piano hammers. It made me laugh out loud.

The classy choice of music (Ligeti, Volans), some of it live, with the pianist Stephen Gosling pounding the life from an onstage Steinway, helped the show along. So did the aural curiosity of a miked stage, allowing the human paintbrushes to make a kind of floormop music too. But what a shame Dance Umbrella didn't think of auctioning the leftovers. A chunk of that colourful canvas would look a treat hung over my stairs.

Covent Garden revivals of Romeo and Juliet don't often spring surprises, but when one of the first-night leads goes injured, anything can happen. Last week, Johan Kobborg's clobbered ankle became Steven McRae's opportunity-knocks moment as the 21-year-old took the honours after little more than a week to learn the part. As a slight, not to say small, dancer at soloist level, McRae might never have got a sniff at a romantic lead, were it not for his near-perfect match to the slight, not to say small, Kobborg, as well as the ibex leap and brilliant feet that had been wowing audiences all last season.

From his first minute on stage, you know his is going to hit the spot. Here, for once, was an impetuous pup we could believe in: a dangerous assembly of rampant hormones and best intentions that could quite conceivably abandon one unsuitable love (the disdainful Rosaline) to light instantly on another (duetting with her fiancé), and arrive in a mortuary only to stab the first person he sees without asking what's going on first.

While McRae was visibly stretched by the long and demanding lifts – even with a Juliet as tiny as Alina Cojocaru – his fizzing solo work cut the fastest, most deliriously buoyant turns I've seen in 15 years of balcony scenes (so fast, in fact, that the show finished five minutes early).

He also offered some uniquely nuanced character observation. When Juliet boldly grasped his hand to her heart to make him feel its nervous beat, teenage opportunism flickered across his features as if to say, "Past first base already!" So young, so male, and so fatally foolish.

Click here for Romeo and Juliet website

'Romeo and Juliet': (020 7304 4000) in rep to 25 Nov.

Further viewing MacMillan's 'Romeo and Juliet' on DVD starring Alessandra Ferri and Wayne Eagling in 1984 (£17.99)