Well, I just tried it and yup, Kik installs with the white background and green text icon while the Play Store (both on the phone and on the web) shows the green background with white text. BUT if you see the screenshots from the Play Store, the Kik logo is green text, so maybe Kik updated the image on the Play Store but not the actual app icon. Since the Play Store's background is white, maybe they wanted to define their icon there more and chose to go for the green background instead.