To make the math easier, computers and consoles usually rounded it to 228, but! -- interference now lines up on every scanline instead of going back and forth and appearing as 'checkboard' noise.

Depending on how the luma signal in higher-resolution graphics modes was phase-offset from the chroma, this meant patterns of bright high-res pixels created color artifacts very visibly and consistently.

(By "high res graphics" we mean 320 pixels across)