五千里苍穹四厘米天青八千米海岸七厘米蔚蓝
[wŭ qiān lĭ cāng qióng sì lí mĭ tiān qīng bā qiān mĭ hăi àn qī lí mĭ yù lán]
It's a creative metaphor combining distance with color descriptions: the vast sky of thousands of miles and only four centimeters blue, the 8000-meter coastline merely seven centimeters blue, conveying the vastness and beauty of nature while also reflecting on personal contemplations and emotions.