For advice on the hull color of the 16-foot models see the REFERENCE section article on that model at
http://continuouswave.com/whaler/reference/16-17/The article gives advice on hull color by production epoch. For 1971 the hull color was just "white."
In order to judge the actual colors of a paint, you need actual paint swatch samples. Do not rely on computer screen images to depict colors, particularly subtle shades of white.
If the hull retains its original color, you can choose a suitable paint by comparing the original hull color to the paint swatches. Clean and buff the original gel coat color to a nice lustre. Then compare the paint to the gel coat color outdoors in daylight from the sun, not indoors and never with fluorescent lamp illumination.