Normally, it would be somewhat easy to use the Change To Color effect to accomplish this, but in your shot you are going to have the problem of other parts of the shot also changing color, because there is so much yellow in the surface on which the glass is sitting, etc.
If you can reshoot in such a way that the egg yolk is the only yellow in the shot, then an effect like Change To Color will do the job for you easily.
That said, go ahead and give the effect a try on your current shot, and see if keeping the Tolerance low allows you to isolate just the yellow of the egg yolk.
Don't see much that would be problematic. Yeah, a bit of masking and some feathering that may take half an hour, but once you have the matte you can use any effect on an adjustment layer to change the hue or colorize it...
If you have Colorista this would be a snap. You can use a color as a matte in the Secondary Color Corrector. I do it all the time. Check out this video. At about 10:45 Stu will change the Yellow newspaper box to Gray.... I use this feature all the time:
edit: had some time this evening and gave it a bit of a try. Took about a minute.