浅诉那抹忧伤遗忘那缕月光
[qiăn sù nèi mŏ yōu shāng yí wàng nèi lǚ yuè guāng]
With poetic nuance, the meaning is along the lines of 'speaking gently about that trace of sadness while forgetting strands of moonlight.' It alludes to reminiscing about moments marked by sorrow but then attempting to let them go, symbolized by letting moonlight fade from memory.