Crocs Classic V1 unisex-child Clogs

What’s the difference between “oyster” and “oyster glitter”? do both really have glitter like it shows in the pictures above or no?

My granddaughter is a size 10 she is 4 years old. What size do I order?

My neice wears a size 3/4 and is 9 years old. What size crocs should I buy?

What size should I order for 4.5 yr old that wears 9 toddler?