Do you consider cerulean high or mid blood? I always considered it high blood since Kankri calls the landdweller nobility "CIPs" but most people seem to split the hemospectrum up into 4ths?
If you’re separating Landwellers and Seadwellers, then the Cerulean-Indigo-Purples do fit into that three-color spectrum that would be considered the Highest of the High. I’m not even sure if the term ‘Midblood’ has any validity when it comes to Alternia, or the strict divide between Highbloods and Lowblods. It may honestly depend on how casteist someone is.
Either way, I tend to consider Ceruleans and Teals BOTH, Highbloods by dividing the Hemospectrum at the middle, and Midbloods if we consider Jades and Olives to be Midbloods as well.