OmniSpectra
Author, you know that Kaioken doesn't actually change the color of Ki, right? This was just put so that people watching know that Goku is using kaioken, but the color doesn't change, only the power changes, so much so that often characters like Krillin l, Gohan, Yancha, among others, say that Goku can use it. the kaioken to defeat a certain enemy, but he is already using it, like in the battle of Goku vs Frieza, or against Reecome, they didn't know that he is using kaioken, only intelligent people like Piccolo could detect the changes in power level and explain which he was already using, but that's it, the kaioken doesn't change his physical appearance, it just amplifies his power.