That is why you always have to do large test swatches before painting, and then view them for a couple of days in all lights. You can never go by the paint chip. I've done a ton of painting and choosing colors can be a lengthy process, with many return trips to the paint store.
Sometimes they can fix a color, but more often than not you will have to pick another color and repaint.
If you choose to try to fix the color you already have, be prepared to go back and forth to the store a few times, and then it still probably won't be what you want. Since the wall is already painted, you only need one more coat -- why not just spend $60 and get new paint? How many rooms are you doing? A gallon should do one coat on most normal-sized rooms.
The best paints for quality and color selection are Behr, Ralph Lauren (both available at Home Depot) and Benjamin Moore. Benjamin Moore sells little sample jars for about 4 bucks. I suggest you try some of the sample jars - and make sure you make your test swatches as big as you possibly can -- the recommended size is 5 feet x 5 feet, in 3 different parts of the room, because colors change depending on the light and will look different on different walls.
By the way, having pink undertones in beige is quite common. When you are choosing colors, the color on the chip should be much greyer than you think you want, because it will then look good on the walls. Any color you like on the paint chip -- choose a greyed-down version of that color, and then it will translate well on the wall.