Responses

Actually, it’s quite original of the author to have the devil "change" his skin color. The devil is originally dark-skinned, but in his human form, he is fair-skinned. During that period, it was "obligatory" for nobles to be as fair-skinned as possible (even applying white powder to their faces) to show they were of noble blood and above common folk, who had to work under the scorching sun.
Or maybe I’m reading too much into it, and the author just wanted to differentiate the devil's form by skin color ( ̄∇ ̄")
One blink he’s white, another blink he’s brown. just stick to only one look for an entire chapter bro