At that very moment, Finn was debating not coming out at all. Perhaps never again.
He'd gone about his normal morning routine - woken up, showered, dressed, etc. - but somewhere in the midst of all that, he'd noticed that he was quite purple. At first, he'd only assumed that someone with a rather poorly developed sense of humour had charmed his mirror, but no. That would have been too simple. No, when he looked down at himself, there was no denying that he was indeed purple, as if he'd decided this morning instead to bathe in a vat of grape juice, and since obviously he hadn't done that, he had to assume that someone person who thought themself terribly clever was playing a trick on him. He could be sanguine about it. Perhaps, privately, he could even respect the audacity of it. But teach a class like this? No. No, that wasn't going to happen.
Of course, the first thing he tried to do was scrub the colour off, but that met with limited success. No success, really, to be honest about it. If there was any change in hue at all, it was only because he rubbed himself red... or reddish-purple, anyway. Feeling decidedly annoyed, now, he resorted to magic, but the charm was no more effective that the washcloth had been, and he was still well and truly purple after three tries and quite a lot of cursing.
Now, he began to consider the source of the problem. He'd first noticed the alarming colour change when he'd dressed. Was it his clothing? He changed them. It made no difference. When he examined them, he could find nothing out of the ordinary about them. What else could it be, then? Had someone switched out his soap for some trick stuff? It seemed to him that he'd heard of a prank like that before... But, no. His soap was perfectly ordinary, so far as he could tell. At the least, it didn't produce purple suds when he lathered it up to test it. Likewise, the water ran clear when he checked it.
"All right, you clever little bugger. How did you manage it?" Finn muttered to himself. He went around his apartment and couldn't find a single thing out of place. It was as if no-one had been here at all, except that he knew someone had, and he was beginning to be angry, now. Someone had snuck into his home like an earwig under the door, like a squirming, spying little worm. It could not be born. He might have chosen to leave his land and to live among humans, but he was still Finnbheara, son of Dagda, and king of the Daoine Sidhe, and he would not be mocked. He would find the culprit.
Finn drew a strong glamour around himself, and was further angered when it only managed to change his complexion from bright purple to unusually pink as if he were highly flushed. He stalked out the door in a foul mood, paying no mind to anything else, so that he nearly tripped over Meda camping on his doorstep. "What are you doing here?" he snapped at her. "What do you want?" He had no time or patience to spare for her this morning.