My ex wife was granted sole, legal custody, a year ago

A year ago my ex was granted sole, legal custody of our 2 minor children 15, and 13, however less than six months later, outside of the court order my ex, gives me back our son, and now I have had him for a year. Ex decides to pull him from his school, where her and I enrolled him last year together and send him to Colorado for 3 months to an undisclosed location with out my permission. My visition through the court order is supervised visition 4 hours a week. What recourse in California family law, do I have with my ex taking our son to Colorado without my permission.