So, you were 90% there already. The things you were missing:
- The ColorRamp nodes should be input to the Emission Shader’s color input. This gives you three different sets of stars on black backgrounds each emitting a single color.
- To mix the three evenly (assuming that is what you want), you’ll just mix 2 of them at a 1:1 ratio, and then mix the result of that with the third shader in a 2:1 ratio.
- I added a compositing node setup that is a quick and dirty try at that 4-point star streaky look, but there’s probably hours of work that could be put into making that look better. Just wanted to give you an idea on how it could look.
The World Material and the compositing setup are included in the attached file. Please let me know if you have any questions.
World Material nodes:
Viewport render:
Compositing nodes:
Final image:
File:
Red White and Blue Stars_01.blend (819.0 KB)
Edit:
To answer your second question (Would you take a different approach?), I think the answer depends on what you are ultimately trying to accomplish. What exactly is that? Just to be able to mimic one of these deep space images?