OPI Fiercely Fiona is a lemon yellow with green tone creme nail polish color. From the Shrek Forever After Collection, Summer 2010, Limited Edition. Product Features Color: Fiercely Fiona OPI Fiercely Fiona is part of the OPI Shrek Forever After Collection. This is a professional quality nail polish and is very strong and durable. OPI Nail Polish works wonders on either natural fingernails or acrylic nails.