The Oxford English Dictionary defines it as a "light purple or lavender colour", which is used for Durham (and Newcastle) academic hoods.
ðɪ ˈɑːksfɚd ˈɪŋɡlɪʃ dˈɪkʃənˌɛɹi dᵻfˈaɪnz ɪɾ æz ˈeɪ "lˈaɪt pˈɜːpəl ɔːɹ lˈævəndɚ kˈʌlɚ", wˌɪtʃ ɪz jˈuːzd fɔːɹ dˈʌɹəm ænd nˈuːkæsəl ˌækədˈɛmɪk hˈʊdz.