"Didst the technicolor yawn" is not a commonly used phrase but it refers to vomiting in a colorful manner. The spelling of "didst" indicates that it is an archaic pronunciation of "did", which is spelled as /dɪd/ in IPA phonetic transcription. "Technicolor" is spelled as /ˈtek.nə.kʌl.ər/ and "yawn" as /jɔːn/. The unusual phrase might be difficult to spell but it remains a fun and descriptive way to communicate a not-so-pleasant action.