The Renegade of the Riviera: Pablo Picasso, Peace and Freedom. Tate Liverpool, to August 30th.

The life and work of Pablo Picasso is rich with paradox. In one version of the Picasso legend, he is an arch-bohemian; a Breton-shirted womaniser living it up on the French Riviera; the first true artistic celebrity. Yet there is also Picasso the genius; the lightning conductor for the spirit of his age, whose 1937 masterpiece Guernica seems to thrill in every atom with the agony and horror of an entire continent about to be plunged into the abyss. Guernica, like Picasso himself, has become public property.

Tate Liverpool’s new exhibition seeks to offer a third view of Picasso: as a serious and committed political thinker and activist, whose artistic production is inextricable bound up with his engagement with politics.

It begins with a relative of Guernica, The Charnel House. Painted in 1944-45, this is a portrayal of the aftermath of war. Where Guernica depicts a massacre taking place – and suggests the potential endlessness of suffering – The Charnel House is a vision of lifelessness. A family lie massacred in their kitchen, beneath a table of food indicating that violent death has intruded permanently into the private realm. A rotund, blank-eyed baby seems to jam its hand into its mouth; an arm reaches rigidly upwards, open-palmed; defensive rather than defiant. Where Guernica screams, The Charnel House is terrifyingly silent.

The exhibition takes the end of the War as its starting point and proceeds chronologically through the remaining decades of Picasso’s life, tracking the moods and phases of his work against the political landscape. But with this approach, subtlety is often lost. The works grouped together as Still Lifes may be more complex than they are given credit for. The many skulls that feature in the works of the decade following the War’s end are interpreted as being memento mori, symbols of death that elegise the millions killed. Certainly, the large bronze human-like cranium, with its misshapen eye sockets and raddled texture, seems to meditate on mortality. But in the painting Still Life with Skull, Leeks and Pitcher, March 14, 1945 the skull seems to be roguish and essentially comic. The humour intrinsic to a work like Lobster and Cat (1965) is also overlooked – the cat trapped between fascination and fear, hissing and arched; the lobster scuttling, claw triumphantly raised – in favour of a political explanation of the cat as tyrant whose greed ultimately brings him into an encounter more powerful enemy.

The curators’ need to extract a fixed political code from Picasso’s shifting, enigmatic visual vocabulary only becomes more pronounced as one moves through the exhibition. This is a vast show (nine rooms in total), and it is hard not to feel that the inclusion of very late works such as those in the ‘Mothers and Musketeers’ room was more for the sake of completeness than for cohesion, particularly when the accompanying text tells us that “The women, especially mothers, represent peace; the musketeers represent war.” This seems unsubstantiated and simplistic, a symptom of the determination of the curators to make their political point even when the evidence is shaky.

At the heart of their argument – and this show does feel argumentative – is the room devoted to the Dove of Peace and its life as a political symbol. While it is made clear that it was the poet Louis Aragon who chose the image for a poster for the World Peace Conference of 1949, not Picasso himself – who declared that “I never could understand how one could make it into a symbol of peace. It is an extremely cruel bird” – the ubiquity of the image in Leftist literature of the time seems to be presented as evidence for Picasso’s commitment to the political left. That his image was used as propaganda does not make Picasso a propagandist. More generally, I would say that the vast amount of newspapers, handbills, posters and other ephemera is simply too extensive and too repetitive to hold the interest of those more interested in Pablo Picasso than in Leftist French media.

This show, impressive in its scope and ambition, is marred by a heavy-handed didacticism. The interpretations offered are frequently too emphatic: The Rape of the Sabines series (1962) is read as a response to the Cuban Missile Crisis, but the nature of this connection is far from obvious. The series could be read as a burlesque on the clash of civilizations, and an anti-war statement, but to read it as an allegory of a very specific moment of political history is tendentious to say the least. The curators continually tell rather than suggest; given the wealth of contextual material assembled here, the viewer could be allowed more space to draw their own conclusions about its influence on Picasso’s work.

There is, it must be said, plenty to enjoy here, if one allows the works to speak for themselves: I could have spent much more time enjoying the deceptively simple vibrancy of Composition 1948, or the unnerving stare, both mischievous and piercing, of Owl With Chair, Ochre Background (1947). But too often this exhibition tries to fix meanings in political terms, terms which inevitably fail to encompass the rich ironies, the troubling ambiguities and, indeed, the sheer strangeness of Picasso’s genius.

Colour Chart: Re-inventing Colour 1950-Today. Tate Liverpool, 13th August 2009

In taking the colour chart as exemplar of the incursion of technology into the traditional processes of visual art, Tate Liverpool’s current show seeks to engage with wider questions about man’s relationship with the machines that surround him, and about the possibility of originality. But this show becomes a far more intriguing and ambitious affair than you might expect from its premise. While there is plenty of abstract work taking its cue from the codes, sequences and number matrices of the industrial world, most notably Gerhard Richter’s beautiful 4096 Colours (1971), and in On Kawara’s anxious, sinister Today series (1966-present), which takes the obsession with order lurking behind industrial process to its conclusion in a series of huge bound volumes of dated colour samples, to my mind the most compelling work here exists on the troubled surface between man and technology, and does not attempt to eliminate the human dimension of creation. The methodological exactitude of Kawara thankfully finds an engaging counterpoint in Edward Ruscha’s Stains (1969), a playful series that mixes order and anarchy: the stains are the result of meticulously catalogued combinations of commonly occurring substances like parsley, Coca Cola and bacon grease. There is a kind of glee in the unpredictability of the resulting colours which stands in stark contrast to the terror that Kawara’s work exudes.

If Karawara’s work, and to some extent Richter’s, exhibits a desire to remove the human element and the unpredictability it entails, other work on show emphasises the human element of technology. Jan Dibbets’ Color Studies (2007), a series of close-up photographs of car bodywork, accepts the uniform nature of commercial design, but it also serves to remind us of how such items become objects of personal expression.

Skin colour is a recurrent theme. In one cabinet, a medical chart of skin tones is displayed, while Byron Kim’s Synecdoche (1991-Present) is a series of panels, the colour of each matched to the skin of a different model. The effect is an arresting combination of the intensely personal, even the intimate, with the depersonalised format of an industrial colour chart, and by extension with the dehumanising connotations of identifying people purely by skin tone. Carrie Mae Weems’ Colored People series, meanwhile, presents a different response to the same problem by emphasising that colour is property of light, not of people.

Meanwhile cabinets display examples of industrial colour manuals, along with volumes on theory of perception and aesthetics, an addition which neatly and unobtrusively situates the show in its theoretical background without making heavy weather of it. Word-spotters will enjoy noticing how the publication of colour charts required a sometimes fanciful expansion of the language of colour into such combinations as ‘billiard green’ and ‘red maple’. Yves Klein’s Peintures (1954) provides a flash of much-appreciated wit: a booklet of colour samples masquerading as a catalogue of full size monochromes, funny as well as prematurely postmodern.

Human and machine; order and chaos; terror and mischief… the coexistence of all these forces makes this show a treat. If there is a weak spot, I would have to point reluctantly to the most recent pieces; Jim Lambie’s ZOBOP! (2006), for example, while intriguing in passing, seemed to have little to offer beyond what the earlier pieces in the show had already investigated. Angela Bulloch’s Ideation and Reflection (2003) feels to me more like updating than genuine innovation. But these are minor quarrels; Colour Chart overall is brilliantly conceived and maintains a warmth and humanity that belies the technical nature of its premise. Perhaps most impressively, it is a show as relevant and enjoyable to colour-mad toddlers as it is to scholars of Theodor Adorno. And it’s not often you can say that.