Dreaming about installing display monitors at a riverside octagonal corporate office building at night with colleagues could symbolize several themes related to your waking life.

1. Work and Collaboration: The presence of colleagues suggests teamwork and collaboration. This may indicate that you are currently working on a project with others or that you value input from your peers in your professional life.
2. New Beginnings: The act of installing monitors can represent new ideas or initiatives being put into place. It might indicate that you are in the process of bringing something new into your work environment or that you are focused on enhancing communication or clarity in your projects.
3. Setting and Atmosphere: The riverside setting could symbolize a calm and peaceful environment, which might suggest that you are seeking balance in your work life. The night setting could represent a time of reflection or contemplation, indicating that you may be working on tasks that require focus and introspection.
4. Structure and Organization: The octagonal shape of the building might symbolize stability and structure. This could imply that you are looking for a solid foundation in your current endeavors or that you are trying to create a well-organized approach to your responsibilities.

Overall, this dream may reflect your feelings about your current work situation, your relationships with colleagues, and your aspirations for innovation and clarity in your professional life. Consider what aspects of your waking life might resonate with these themes, and how you can harness this energy to move forward in your career.