Things You'll Need
Instructions
Turn your computer on and open up Adobe Photoshop, GIMP or Paint.net. Photoshop is a program you buy; the two others are available as free downloads and are similar to Photoshop.
Click "File" in the navigation bar and select "Open" from the new menu. Use your computer cursor to navigate to the folder and highlight the file you want to open. Click "OK" and the image will open in the program window.
Click "Enhance" in the navigation bar and select "Adjust color" then "Color variations" from the drop-down menu. There will be three color adjustments for increasing or decreasing the level of each channel. By increasing or decreasing the red, green and blue channel, you can remove the yellow color cast from your picture. Once you have adjusted the picture to your satisfaction, click "OK" and the program will adjust the picture and close the window.
Click "File" and select "Save as" from the menu, give your edited picture a name and save it to your computer.