All loyal Pioneers know that the colors of Marietta College are Navy Blue and White, but tracing them back to an exact date of official adoption is an interesting journey into the institution's archives.
For instance, if one consults the Marietta College Olio, a monthly publication of Alpha Kappa and Psi Gamma Literary Societies constituting the College's student newspaper of the late 19th century, there is a reference in November of 1892 to "our new, beautiful and artistic dress, printed in college colors." The interesting thing about such a claim is that the cover being described was rendered in red and white!
For all that, less than a year later, in June of 1893, the same cover described in such glowing terms the previous fall, was published not in red and white, but in dark blue and white.
By November of 1894, descriptions of upcoming grid iron contests between the Morgantown University and Marietta listed the College's colors as "white and blue."
Two years later, in 1896, a description of preparations for a Thanksgiving Day game against Ohio Northern included efforts by local merchants to "decorate their stores with the blue and white of Marietta College."
So it would seem that well before the turn of the century, Pioneers were rallying around the Navy Blue and White. This is despite the fact that a 1947 survey of colleges prompted a somewhat less certain response from Marietta officials who had to admit that "the year of the adoption of the colors is a bit doubtful." The response provided by Marietta in answer to the query was "approximately 1899."
Sources: The Marietta College Olio, The Wheeling Register, correspondence to Henry L. Snyder.