My guess is illegal if not done through a licensed dealer. You should post this question in the legal forum if you want anything other than an unqualified opinion. It is a long shot that you'll find someone hear that has experience in this.
Must be legal. About 5 years ago, in either Jarabacoa or Santiago (can't remember) I was driving by a park and saw guys gearing up for a paintball battle.
Air rifles and air pistols require licenses in this country......not sure where a paintball gun comes in on this, but it is generally an air pistol.....
so is my airsoft semi auto plastic bb shooter legal here....i know my maids hate it...as i use it indoors and spray my apt... of course its better when i drive around shooting at groups of youths who love it....