How to split string into a dictionary

I have this string

string sx="(colorIndex=3)(font.family=Helvetica)(font.bold=1)";

and am splitting it with

string [] ss=sx.Split(new char[] { '(', ')' },
    StringSplitOptions.RemoveEmptyEntries);

Instead of that, how could I split the result into a Dictionary<string,string>? The resulting dictionary should look like:

Key          Value
colorIndex   3
font.family  Helvetica
font.bold    1