These are the only comparisons I have been able to locate. You may be able to create more by going with SU cardstock in between...GK to SU to PTI
Passionate Pink - in between Raspberry Fizz and Hibiscus
Innocent Pink - exact to Sweet Blush
Just Peachy - exact to Melon Berry
Bubblegum Pink - "pretty close" with a touch more pink to Lavender Moon
Red Hot - more brighter red to Pure Poppy
Lipstick Red - exact to SU!
Ridinghood Red
Turquoise Sea - exact to Hawaiian Shores
Ocean Mist - tiny bit bluer than Aqua Mist
Green Apple - touch lighter than Avocado
Grass Green - exact to New Leaf
Lemon drop - yellower and brighter than Lemon Tart (much prettier than Tart)
Wild Dandelion - darker than Summer Sunrise, almost exact to SU! Daffodil Delight
Dark Chocolate - darker than Dark Chocolate
Crafting in Croatia: Color Comparisons: GinaK Designs, SU and PTI Cardstocks