Colby edited a department in the "Beatrice Express" called "Woman's Work," and in 1883, she founded, published, and edited "The Woman's Tribune". For several years, she was deeply interested in the movement for woman's enfranchisement, devoting her journal to the advocacy of this reform. "The Woman's Tribune" took the prize at the Paris Exposition in 1900 for its neatness and workman-like appearance, and it filled an important place in the history of the suffragist cause, being for a time the recognized organ of the National Woman Suffrage Association. A contemporary and friend of Elizabeth Cady Stanton, Susan B. Anthony, and Dr. Mary Edwards Walker, Colby lectured extensively not only to general audiences, but before legislative and congressional committees. In 1888, at the time of the great International Council of Women in Washington, D.C. Colby published the "Tribune" daily during the week of the council, and continued it through the Woman's Suffrage Convention the following week. It is probably the first instance of a daily woman's paper being published by a woman. During the period of 1885–1898, she served as president of the Nebraska Woman Suffrage Association, and in 1895, she served as the chair of the Federal Suffrage Committee. She spoke in behalf of the soldiers of the Spanish–American War (1898); during the Spanish–American War, she was officially appointed as war correspondent, the first woman to be so recognized. She was also an advocate of peace at the Panama–Pacific International Exposition in San Francisco, California in 1915.