暮月凉情
[mù yuè liáng qíng]
Combining dusk ('暮' -mu), moon ('月' -yue) and the cool/cold emotion ('凉情'), this can be translated as 'Twilight's moon and cooling love/affection'. It paints a romantic, melancholic picture of waning feelings as if the light from a moon fades towards the end of a romantic period or significant chapter.