T he children’s nursery rhyme I Can Sing a Rainbow swirls at the back of my mind as I wander the bright and beautiful rooms of art collector Ruth Evans’s north London home. Red and yellow and pink and green, purple and orange and blue – they’re all here. Evans (who is also the chair of Stop Scams UK) has lived in this Victorian terrace for 30 years and this is her third refurbishment. “Each renewal of the house marks a stage in my life. First it was a comfortable home in which to raise a child; then, in my 40s, it was about bringing my own sense of style to where I live; and now it’s the rest of my days: a culmination of everything I’ve learned over the years – the aesthetics, colour and art that make the house sing.” For this latest upgrade, Evans turned to her friend, the interior designer Mika Burdett. “I grew up with the generation who had great regard for minimalism,” Burdett says.…