Converting int to enum of smaller size underlying type

An int can be converted to an enum value by simply casting it to the enum type. But what is the behavior of this conversion if the enum's underlying type is of smaller size than int, and the value being converted is more than the max range of the enum's underlying type?

enum Color : byte { Red=0, Green, Blue }; 

Say we convert an int to Color:

int num = 257;
var color = (Color)num;

What would be the value of color above?