气态氧无色、无臭、无味的气体。

液态氧为淡蓝色液体，沸点-182.96℃，90.188K（1个大气压）。

固态氧熔点-218.79℃，54.36K（1个大气压），

总***有6种不同的相态的固体氧是已知存在的：?

α相：浅蓝色，在1个大气压下，温度低于23.8 K，单斜晶体结构。?

β相：淡蓝色并夹杂粉红色，在1个大气压，温度低于43.8 K下存在，菱面体晶体结构（在室温及高温压力开始转变为O4）。?

γ-相：淡蓝色，在1个大气压，温度54.36 K下存在，立方晶体结构。?

δ相：橙色，通过施加9GPa的压强，在室温下存在。?

ε相：暗红色到黑色，在室温下，压强超过10GPa下存在。

ζ相：金属的形式，在压强超过96 GPa下存在。

固态氧颜色描述原文资料参考（以上中文描述翻译于这段文字）：

————For?wiκiрediα————

A total of 6 different?phases?of solid oxygen are known to exist:

α-phase:?light blue?— forms at 1 atm below 23.8 K,?monoclinic?crystal structure.

β-phase:?faint blue?to?pink?— forms at 1 atm below 43.8 K, rhombohedral crystal structure, (at room temperature and high pressure begins transformation to tetraoxygen).

γ-phase:?faint blue?— forms at 1 atm below 54.36 K, cubic crystal structure.

δ-phase:?orange?— forms at room temperature by applying a pressure of?9?GPa

ε-phase:?dark-red?to?black?— forms at room temperature at pressures greater than 10 GPa

ζ-phase:?metallic?— forms at pressures greater than?96?GPa

? It has been known that oxygen is solidified into a state called the β-phase at room temperature by applying pressure, and with further increasing pressure, the β-phase undergoes?phase transitions?to the δ-phase at 9 GPa and the ε-phase at 10 GPa; and, due to the increase in?molecular interactions, the color of the β-phase changes to pink, orange, then red (the stable octaoxygen phase), and the red color further darkens to black with increasing pressure. It was found that a metallic ζ-phase appears at 96 GPa when ε-phase oxygen is further compressed.

顺便贴些液氧的实物照片作为参考（蓝色很淡）：