Dear
MechanicalMan64 and other participants in this thread, there are two factors that make the OP's request fraught with difficulty, if not impossible:
1) The "goal" photo is obviously taken under tungsten (ie, very warm colored) illumination. If you don't believe this, bring the goal image into PS and use the eyedropper tool to measure the RGB values at anything in the photo that you think should be white (except overexposed areas). What you will see is that the RGB values of even these supposedly white areas are all (with one small exception) higher in R than the either G or B. In other words even the presumably white areas are unnaturally warm in the goal photo.
Since these areas are bathed in orange light (almost certainly from tungsten light bulbs), you can be sure that the nearby icing is also bathed in the exact same orange-ish light. Therefore the peach color that you see in the goal image's icing is almost certainly misleading. Specifically, if you viewed the same cake in a correctly color balanced photo, the icing will look cooler. Exactly how much cooler is anyone's guess.
Therefore, saying that you want to make the icing color in your fairly well balanced 1st photo the same as the color in the poorly color balanced 2nd (goal) photo is almost guaranteed to give you unexpected, if not disappointing results.
2) The second factor is that with the exception of professional photographers and advanced amateurs in photography and the graphic arts, very, very few people have monitors which are well calibrated with respect to colors and tonalities. At minimum, to achieve this, you have to purchase a separate, good quality hardware calibrator (usually at least a couple of hundred dollars), a good (ie, "calibratible") monitor (several hundred $$$ more to a couple of thousand $$$ more), and a viewing area with controlled, time-invariant, illumination.
So, even if the goal photo had been taken under studio lighting with perfect white balance, the fact that the OP likes the color of icing when viewed on his (almost certainly) uncalibrated monitor means almost nothing.
I'm sorry to be the bearer of bad news, but color is a much more complicated subject than most people think, especially when we are talking about relatively small changes in hue, saturation and lightness such as have been discussed in this thread.
HTH,
Tom M
