Any Yarn type and color will work as long as you use a corresponding hook with that yarn.

I used “ Honey Bunny” (50 m = 100g) in:
Baby Blue (color code: 75) (50g)

Please note that this pattern is crocheted in continuous rounds. Use a piece of yarn (30cm) in contrasting color as a stitch marker to mark your last stitch in each round.
This marker yarn will provide a clear marking along the middle of the Dolphins back.