The 42-year-old, who raises Alexia, 14, Isabella, six, Gia, four and 23-month-old Stella with wife Luciana, believes his grey hair are all down to parenthood and often teases his daughters about it, reported Us magazine.
"I point out all of the grey and I say to my daughters, 'You did this and you did this and you did this'. They really think it's funny. They dyed the grey out for 'We Bought a Zoo', but I was like, 'I like my grey hair'. I'm proud of it," he said.
Right now Damon has his head shaved for an upcoming role but says it is not a problem as he has a "beanie".