If you go to the store front and click on the colorant selection, then find bubblegum in the X2 catagory and click on it, you'll see a couple examples. One is a little stronger than the other. They are both opaque. This alone will work on your behalf.
Try a 4 ounce mix using a drop of plain pearl and maybe 3 white and mix well. Then just take the tip of your red dispenser over the end of whatever you mix with and stir taht amount into the white mix. Red is a strong color and will over-power a pink in a blink so you want to add just a breath of red at a time. When that 4 ounce cup "just" shows some pinkish to it, cook it. Remember, cooking will deepen the colors seen in raw plastic so at the first hintr of blush in the white, heat it up. If you need to add more red you'll know it as soon as the plastic "turns" while its first heating and you can repeat this mere staining the white even after the initial cooking by adding just a wisp of red at a time. Go slow and you'll get it down.