Colorado became the 38th state on August 1, 1876, but did not hold its first election until October 3rd of that year. John L. Routt was the sitting territorial governor and that remained his title until November 3rd when he was sworn in as the state's first governor.
Source for Popular Vote data: Colorado General Assembly. The Legislative Manual of the State of Colorado, Colorado General Assembly (https://archive.org/details/legislativemanua00thom/page/234/mode/2up?view=theater) (accessed 28 Nov 2023)