in roygbiv, the way sir isaac newton intended it, „blue“ refers to sky blue (vaguely something near or a bit more blue than #00ffff), and „indigo“ to royal blue (#0000ff), but (from what i can tell) many people today then interpret the „blue“ here as meaning royal blue (#0000ff), and the „indigo“ here as meaning the color between royal blue and violet (#4000ff). i think the original system makes more sense here, but consistency is still better than being half-right imo, so we should either replace roygbiv with roygcbv (cyan and blue to match modern terminology) or rgi and bmyk (change blue and cyan to indigo and blue), (i acknowledge no one is going to do this, but this is social media! i can post walls of text online when most people don’t care about the subject, and if people say they didn’t ask, i can just tell them that if they don’t care, i’m not talking to them! it’s a perfect system!)