Step-By-Step Instructions:
1. Open a photograph that has a blue sky and clouds.
2. Click the "Edit in Quick Mask Mode" button.
3. Select the Paint Brush tool and choose Black as your color.
4. Choose an appropriate size paint brush and paint the entire sky. In Quick Mask Mode, your paint will be a transparent red.
5. Click the "Edit in Standard Mode" button.
6. Goto Select > Inverse. The sky should now be selected.
7. Goto Image > Adjustments > Color Balance.
8. Adjust the "Cyan to Red" sliders under Shadows, Midtones, and Highlights until you get the sunset color you want.
