Koni question

["R. Wiratorn" <withu@loxinfo.co.th>]

        Hi
                Would you please tell me the differrence between
        the red Koni and the yellow one ?
                I use the yellow in my S4, it make the car as stiff
        as a truck.
                I must change it, but not sure whether Boge progas, turbo
        gas, or the red koni.

                                                thanks