The simplest way to re-balance the color in your photo (and remove the yellow cast) is to use the Basic Edits > Colors tool, click Neutral Picker and then click on a spot on your photo that should be white (or gray). This will balance all the colors in your image to reflect that.
You can achieve similar results using the Pro tab > Curves and Levels tools, however this requires a higher level of playing around. It can however achieve a more fine-tuned result, and you may want to use the Neutral Picker tool in combination with these.
Regarding the 24 pages of search results – sorry about that, it was including our Ribbet Lab pages as well, however I’ve now updated this and the results should now be far more relevant and concise.