Stadium light, nighttime photography can cause your camera to produce some strange image colors. The best way to prevent this is to adjust your camera's white balance setting when the automatic setting just doesn't get the job done. The first image below was shot using the "Flash" white balance setting on my Nikon D300. Although the colors produced were better than when using the "Automatic" setting, there's still a yellow color cast within the image.
The second image below was shot using the white balance manual setting at 4000K on the D300. Notice how this photo contains more natural colors. The player's skin tone seem appropriate. Also check out the color of the turf field. It's a green field, and it looks green. but it's yellow-ish in this photo.