Colfax, WA has a population of 2,851 and is the 9,064th largest city in the United States. The population density is 763 per sq mi which is 553% higher than the Washington average and 743% higher than the national average. The median age in Colfax is 43 which is approximately 15% higher than the Washington average of 38. In Colfax, 58% of the population over 15 years of age are married, 94% speak English and 1% speak Spanish. 52% of Colfax residents were born in Washington, 45% were born out of state, 1% were born outside of the United States and 2% were foreign born.