How can Mutation's affect Protein making?

-Most of the Time, it will have a very Small Effect on the Protein that Gene codes for, so that means the Function continues out normally -Some times it can slightly Alter the Phenotype, like for example the Eye Colour can be changed due to a Mutation, but not Drastically -Rarely, it can be Massive, and really affect the Phenotype, an Example is the Genetic Disorder: Cystic Fibrosis