In this Photoshop tutorial the instructor shows how to fix colors. It looks bad to have dull colors in your images. Now open the image in the Photoshop and go to image adjustments. Go to curves and start playing around with the curves in the RGB mode. When you change the curve you can see the change in the original images. Now adjusting the colors in the curves tool play around with the colors and this will get the colors brightened up. There are no stead fast rules but you need to play around with colors to get the desired effect. This video shows how to fix dull colors in Adobe Photoshop.