On May 6, 1911, the Colorado State Legislature passed Senate Bill 118, designating a new Colorado State Flag. That piece of legislation also included a section explaining, "10 Significations," of the flag which are reprinted here in full:
The New Colorado State Flag has 10 significations:
First -- The red C stands for Colorado, a Spanish word, meaning red.
Second -- C stands for centennial. Colorado was admitted to the Union in the year 1876-- the one hundredth anniversary of American independence.
Third -- C stands for columbine, the state flower of Colorado.
Fourth -- The gold center symbolizes the glorious all-the-year-round sunshine of Colorado.
Fifth -- The aureate center also represents the most precious of metals, gold, in the production of which Colorado excels all other states.
Sixth -- The Yale blue stripes stand for the ever-smiling skies of the Rocky Mountain region.
Seventh -- The white stripe typifies the white metal, silver in whose production Colorado also leads the entire galaxy of states.
Eighth -- The white stripe further represents the snowy peaks of the Rocky Mountains.
Ninth -- The Blue and White stripes together give us two of the delicate colors of the exquisite State flower, the columbine.
Tenth -- The interlaced gold and silver cords symbolize the union and harmony of the sterling people of the Centennial state.
To learn more about how Colorado's State Flag came to be, check out The Story Behind Colorado's Iconic State Flag and the Minnie F. Wall Papers at Denver Public Library's Western History and Genealogy Department.