你深情似海却不曾为我而蓝
[nĭ shēn qíng sì hăi què bù céng wéi wŏ ér lán]
'You whose love runs as deep as the sea yet it never turns blue for me' expresses unreciprocated affection; even with someone capable of immense feeling, the direction it flows towards is not oneself. Blue here carries multiple nuances – depth, infinity and also associated with melancholy.