<prompt> Translate the following text to EnglishRangi zao nyembamba, umbo lao lenye kuvutia, na nyuso zao zenye nguvu na zenye kuonekana kuwa halisi, zinaonyesha kwamba sanaa ya Byzantium ilifanikiwa sana kabla ya kuharibika.  <response>: Their subtlety of colour, liveliness of posture, and strong, lifelike faces record a last remarkable flowering of Byzantine art before its descent into decadence. 