We're thinking that, like, an #eee or an #eef rather than a pure #fff, very short distance. We know for a fact that very often people reach for slightly off-white and off-black. That's from color design bible. Do #111 or #eee. That suggests we should be slightly off white/black for this. but it doesn't tell us exact value
let color1 = new Color("#111");
let color2 = new Color("black");
let color3 = new Color("#eee");
let color4 = new Color("white");
color1.deltaE(color2, "76");
color1.deltaE(color2, "2000");
color1.deltaE(color2, "ok");
color3.deltaE(color4, "76");
color3.deltaE(color4, "2000");
color3.deltaE(color4, "ok");