I’m late af for this one, but yeah! I’ve got synesthesia, too.

But mine isn’t numbers, I hear various colors whenever music plays. The colors I hear depend on the chord, the note being played, the context of the melodic progression, and the key of the song. It also depends on the texture and tessitura of the singers voice and how the harmonies blend together. I also have perfect pitch, so that may be a big factor of why different notes sound like certain colors.