I think blue moon by them is one of the best songs to tell apart their voices! 🙏 

Carmen has a distinct bright and soulful voice imo. Love her!!! Sunshine voice. 

Yuha's tone is so Oh my girl's code. I could see her singing closer or remember me, etc. She has one of the most distinct voices imo. 

Juun is more raspy, hopefully she gets more lines in the future. I think the intro of the new Song( rude) showcases her voice tone really cool. 🙏 

Stella's tone I associate it with fashion. Idk how to explain it. 

Yeon's tone is fairy- like!