Colorado is about 344 times bigger than New York City.

New York City (including all five boroughs: Manhattan, Brooklyn, Queens, The Bronx, and Staten Island) is approximately 781 sq km, while Colorado is approximately 268,627 sq km, making Colorado 34,295% larger than New York City.
Tip: This to-scale comparison of New York City vs. Colorado uses the Mercator projection, which distorts the size of regions near the poles.