Colours matter very little to none for regular osu! gameplay, aside from visibility of approach circles. Even in this case, most people only perceive motion strongly in the LUMA domain, not CHROMA, so those of us with regular vision will still face much the same problems. These problems ought to get caught in the beatmap modding process.
I believe the choice of taiko colours will still provide a strong contrast for most types of colour deficiencies.
I believe the choice of taiko colours will still provide a strong contrast for most types of colour deficiencies.