There's not much time to write.  It's over 70 degrees,  the sun is shining, the sky cloudless and the lido's cool ripply blue water beckons.  The government wants free swimming for all - it's already part of the primary curriculum - but there aren't  enough  outdoor watery oases like the Brockwell Park Lido where swimmers from 0 to 90 plus can get fit and chill out.  My season ticket here is worth more than a hundred pairs of Manolos in terms of well being. A few lengths and a dry-off in the sun are guaranteed to remove the jitters or bad humour.  Looking at all the  blue below and above my breast stroke  makes me think of what a brilliantly versatile and natural decorating tool this colour is.

From deep hyacinth to very pale ice, blue comes  in a myriad of shades. I think of how  blue turns to lavender when mixed with violet, or  turquoise when blended with green. Take a cue from the fashion world and look at the soft blues that characterise denim as it is washed and worn. These shades adapt as easily to home furnishings as they do to jeans and jackets.

My favourite blue dream-scheme is  walls in sludgy grey/blue offset with white painted furniture,  blinds  in blue and white ticking  and bowls of cut herbs.  Make your own blue story by adding blue pigment to a white base, like my friend Hermione who  repaints her beach house in Portugal, every spring with limewash tinted with blue.

And as it's the time of year for alfresco feasts, a  blue and white checked tablecloth is an important part of my kit, whether it's to spread out at a picnic on the beach, or to make the table look jolly for  an everyday meal. Blue and white checks are prosaic, pragmatic and never look out of place.