他心里有片海却不会为我蓝
[tā xīn lĭ yŏu piàn hăi què bù huì wéi wŏ lán]
Expresses a deep sense of disappointment where someone feels their loved one has an inner world ('a sea') rich and deep inside but refuses to change or adapt feelings specifically for them, indicated by not turning blue, a metaphor for caring or loving deeply.