David Beckham has shown off his former platinum blonde hair in a sweet family photo with his family.MORE: Fire breaks out at David Beckham and Guy Ritchie's pub - detailsThe football legend, 46, marked his mother's birthday on Saturday with a trip down memory lane, posting a throwback of the two of them and younger sister Joanne.The grainy image shows David as a youngster flashing a toothy grin to the camera while sporting a crop of white-blonde hair while his mother and sister sit beside