After a little bit of thinking, I have some comparisons to Enya and Lola.

Enya is similar to Yellow Diamond. 

They're both brash, demanding, takes her job seriously and they somewhat resemble anger. 

And Lola is similar to Blue Diamond.

Those two have something to do with grief, sadness and how they're emotional. 

Ghasts tend to be extremely emotional and Lola used to spread joy through the Nether through her wonderful singing voice but after Herobrine's attack, she spreads despair through her crying and eventually attacking humans. 

Their relationship isn't as strained as Yellow and Blue but they do have disagreements with one another. 

They do care for each other as fellow leaders but they never really became close. 

They just see each other as acquaintances and nothing else. 

While Lola is known to deeply care about those she's close to, she cares for Enya to a certain degree.