New Jersey's Flag History
The beautiful buff color of the New Jersey State flag dates all the way back to 1779 and the New Jersey Regiments mustered for the Revolutionary War. The color was chosen by General George Washington when he was directed by the Continental Congress to prescribe the uniform for the regiments of the New Jersey Continental Line. General Washington directed that the coats of the soldiers should be dark blue faced with buff. These colors were chosen by General Washington to honor the original Dutch settlers of New Jersey. Dark Blue (Jersey Blue) and Buff were the colors of Holland or the Netherlands.
On February 28, 1780, the Continental War Officers directed that each regiment should carry two flags; one that of the United States and the other a state flag that should be the color of the Uniform facing and the New Jersey State Flag has carried that color with it for over 200 years.
In 1896, New Jersey made it official and properly described the New Jersey State Flag in a joint resolution of the legislature. The flag is described as "... shall be of a buff color, having in the center thereof the Arms of the state properly emblazoned thereon".
Link here to the New Jersey State Historical Society for facts, figures and history of New Jersey.