You need to find the Town's park rules.
I am a former federal and State prosecutor and now handle criminal defense and personal injury/civil rights cases. Feel free to check out my web site and contact me at (212) 577-9797 or via email at Eric@RothsteinLawNY.com. I was named to the Super Lawyers list as one of the top attorneys in New York for 2012. No more than 5 percent of the lawyers in the state are selected by Super Lawyers. The above answer is for informational purposes only and not meant as legal advice.
Paintball does not appear to be allowed in any Yonkers park.
The answer provided to you is in the nature of general information. The general proposition being that you should try to avoid a bad outcome if you can.