When it comes to popular colors and designs for heel sandals for girls, fashion trends can vary based on personal preferences and current fashion seasons. However, here are some popular options:

1. Neutral Tones: Shades like nude, beige, tan, and taupe are versatile and can be paired with a wide range of outfits. They offer a timeless and elegant look.
2. Metallics: Metallic colors like silver, gold, and rose gold can add a touch of glamour to heel sandals. They can be worn for both casual and formal occasions.
3. Bold Colors: Vibrant hues such as red, blue, yellow, or pink can make a bold statement. These colors are eye-catching and can add a pop of color to any outfit.
4. Animal Prints: Animal prints like leopard or snake prints are quite popular in footwear fashion. They can add a touch of wildness and a trendy element to the heel sandals.