Using Photoshop's "Match Color" tool brings out the color in your astro image. This tool is typically added during the final steps in processing.

The use of this tool is simple. Click IMAGE --> ADJUSTMENTS --> MATCH COLOR...

From the Match Color Screen Slide the "Color Intensity" knob to your taste. I like using values from 120 to 130.

Here are some examples, and values:

Original Image
130
160
200

As with any tool, adjust to your personal taste.

Don't use Hue/Saturation! Use "Match Color" next time to enhance your astro image color!