Help with Custom Outputs?

Hi! So I am messing around with the custom_nodes python example that comes with blender. I am trying to get my node to have an RGB output and I am not sure how to go about this. I have tried:

def init(self, context):'NodeSocketColor', "RGB")
        self.outputs["RGB"].default_value = (0.2, 0.8, 0.8, 1.0)

but it doesn’t show me a color when I use the viewer node in the shader editor. What am I doing wrong? Thanks in advance!