Based on the limited information provided ("Blue" by Yung Kai), pinpointing precise genres is difficult without analyzing the song itself. However, considering the artist's name (Yung Kai) suggests a contemporary hip-hop or R&B influence. The title "Blue" hints at a melancholic or introspective mood. Therefore, potential genres could include:

• Melodic Hip Hop: This genre blends the rhythmic elements of hip-hop with more melodic and often emotionally driven vocals. The "blue" theme aligns well with the introspective nature often found in this subgenre.

• Sad Rap/Emo Rap: If the song leans heavily on lyrical content expressing sadness or emotional vulnerability, it could fall under this category. The emotional weight suggested by "Blue" fits this description.

• Alternative R&B: This genre often incorporates elements of soul, pop, and electronic music, creating a more experimental and atmospheric sound. The title could suggest a departure from typical upbeat R&B, potentially fitting into this alternative space.

• Trap R&B: A blend of trap beats and R&B vocals, this genre can range in mood, but a song titled "Blue" might feature a slower tempo and more melancholic melody than typical trap.

• Cloud Rap: If the song features hazy, atmospheric production and introspective lyrics, it could be categorized as cloud rap. The title "Blue" aligns with the often dreamy and melancholic atmosphere of this subgenre.

To be more precise, a Music Genre Generator tool would require access to the audio file of "Blue" by Yung Kai to analyze its instrumentation, tempo, harmony, and lyrical content. This analysis would provide a more accurate and detailed genre classification.