I heard that the Prophet was described as Al-Azhar, and this explanation was given to me: “When a man is Abyad (white) (in complexion) without anything of redness (Humrah), and it is not radiant, but it is of the color of plaster (Al-Jiss), then it is ‘Amhaq’. And if it is white (Abyad), its whiteness (Bayad) being pleasing with a yellowish tinge (or radiance) in it, like the color of the moon and the gems, then it is ‘Azhar’. The narration of Anas in the description of the Prophet, sallallaahu 'alayhi wa sallam, states, “He was ‘Azhar’ and not ‘Amhaq.’” What does Ahzar mean in complexion? Like, what did they mean like a yellowish tinge/radiance? Does it mean an olive skin tone? Did the Prophet have an olive complexion?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger. 

Rabee‘ah ibn Abi ‘Abdur-Rahmaan narrated, “I heard Anas ibn Maalik describe the Prophet saying, ‘He was of medium height amongst the people, neither tall nor short; he had a fair white color (Azhar), not absolutely white (Amhaq).’” [Al-Bukhari]

Azhar means that he had a white complexion mixed with redness; Ibn Hajar said, “Azhar means white imbued with redness. This was explicitly mentioned in another hadeeth by Anas as well, which was reported by Muslim, Sa’eed ibn Mansoor, At-Tayaalisi, At-Tirmithi and Al-Haakim, and it was narrated by ‘Ali, who said, ‘The Prophet was white with his whiteness imbued with redness.’”

He also said, “What is meant is that he was not extremely white and not extremely dark, but his whiteness was mixed with redness.”

An-Nawawi said, “The Amhaq is the person who is extremely white, like the color of lime. He is unpleasant to see, and the person who looks at him might think that he has vitiligo.”

Allah knows best.