Good Morning, Not sure if you are still inquiring about the origin of the last name "Arreguin", but I have also been searching so I can keep a record for my children & grandchildren. I read the name derives from the area in between France & Spain. Funny, my grandchildren have blue & green eyes, my children have brown eyes, their bio father has honey color eyes, all dark hair. Check out the internet to see the name of the mts. makes sence when you look up the meaning of Arre.