Color Change and Background

[jimlolo]

This is a night sky imge of andromeda. Can anyone suggest what I can do to get this right? I want the background sky to be darker, and change the blue to red/orange/gold.

Thanks.

[Myra Ferguson]

Here's one way to make the background darker and change the blue to red/orange/gold:

1. Apply a Levels adjustment layer (click the middle icon at the bottom of the Layers panel that looks like a black and white cookie and select Levels...)
2. Under the histogram (the graph) drag the left (darkest) indicator to the right to about 80 (the value will show up in the box below it on the left)
3. Adjust the midtones if you like by dragging it
4. Select the Gradient tool (G)
5. Click the gradient in the Options bar (if the Options bar isn't showing go to Window > Options which is at the bottom of that menu)
6. In the Gradient Editor, open the Oranges presets folder and select Orange_05
7. Drag the orange color stop on the right to the middle (to Location: 50)
8. Click on the right where the orange color stop was to add a color stop
9. Click the orange color to open the Color Picker and change the color to red
10. Make a new layer
11. Draw the gradient from the center outward
12. With the Selection Tool selected and the layer selected, scale the rectangle and rotate it and position it to align to Andromeda
13. Control (Win) / Command (macOS) click on the thumbnail of the gradient to load the selection
14. Go to Select > Modify > Feather and enter a value (around 40)
15. Add a Layer Mask by clicking the 3rd icon from the left at the bottom of the Layers panel
16. Further modify the mask with a soft brush set to black to use around the edges
17. Change the blending mode in the Layers panel to Hue