The small linking sound /w/ is written o before a, ă, e (hoa, hoặc, hoe) and u before the other vowels (huế, tuy). After q it is always the u of qu, written once: quan sounds like toán, quân like tuần.
hoa · hoặc · khoẻ · huế · tuyết · quan · quân
Quick answers
How do you pronounce Huế?
Block by block: ê → uê → h → huê → sắc → huế. Tone: sắc (acute accent · high rising). Read each block aloud, then compare with the recording, in a Southern or a Northern voice.
What tone is Huế?
sắc (acute accent · high rising)
Is Huế said differently in the South and the North?
Both accents say Huế as it is written.
What does “hue” mean without the marks?
Without the marks, hue can be several words: huệ (tuberose (flower)), huề (draw, tie (game)), huê (flower). The marks decide which one.