The Colorado Department of Education only accepts content knowledge tests administered by PLACE or Praxis II. PLACE was designed and developed for Colorado, whereas Praxis II is a nationwide test.
Please check that the test for which you are registering is approved by the State of Colorado and accepted for the endorsement that you are seeking. The following link will take you to a list of CDE worksheets that will help you determine which content exam is right for you: CO Test Requirements
Note: Candidates seeking a Special Education or Elementary Education endorsement must take the PLACE or Praxis II exam for Elementary content.