oftentimes, i see merlin as blue. it's kind of a logical conclusion, seeing as that is a colour he is often dressed in throughout the show, and we have the "blue and red" contrast of merlin and arthur that kind of lends itself to that interpretation.
the official colours of the pendragon crest, and thereby the official colours of camelot, are red and gold.
arthur is red. we know this pretty apparently from his costuming-- red tunics, red cape, red necklace. but we're diving into metaphor, here, and within the framework of the show-- of arthur and merlin being two sides of the same coin, opposites and yet one whole-- arthur as red becomes even more apparent.
because red is a colour steeped in history, here, of victory, of war, of nobility. roman soldiers would paint their bodies red after a victory on the battlefield. in medieval history, red was often a royal colour because of its obvious association with blood-- specifically, the blood of christ (which is why cardinals wear red), and was worn by royalty to represent the divine right of kings. charlemagne, notably, wore red shoes at his coronation and painted his palace red. (of course, charlemagne was some 300 years post the time of arthur, but it still stands to reason that the iconography of red didn't change that radically in that time period). and, of course, if we're following arthuriana, arthur was the one who made y Ddraig Goch, the red dragon, his battle standard. (but then we go into the fact that bbc merlin is an anglicized version of a welsh piece of folklore, so of course the pendragon dragon is gold instead, but I am not going that route right now. maybe later. bear with me.)
but even just outside of red's historical context, red's symbolic meaning (which, of course, can't completely be divorced from its historical context, but i digress) is purely arthur. love, passion, fire, blood, courage, sacrifice, arthur, arthur, arthur.
it's interesting, then, that someone who is supposed to be the literal, physical embodiment of his kingdom (the king as a symbolic vessel for that which he rules) is not seen to be coded with both of its colours. sure, arthur wears the crest on several pieces of his clothing-- his gauntlets, his cape. but we never see arthur in just gold. he obviously favours red, as all the pendragons do (morgana's literal favour to sir owain, in the episode with tristan de bois, is red).
we never see merlin wear gold, either. merlin isn't one to wear jewelry (gods know i would pay to see it), and for a servant to be dressed in gold would be. Well.
but merlin's magic is gold.
we see this, very literally, every time he performs magic. his eyes flash gold. it would be kind of a moot point if the idea that eyes flashing gold were a universal character trait amongst magic users in the show, but it isn't. first that comes to mind is the episode with sophia and the sidhe, whose magic turns their eyes red. several magic users throughout the show use magic without their eyes changing colour-- nimueh is one.
so it's not a consistent trait of those who use magic. magic doesn't universally turn your eyes gold within this narrative framework. but it does to merlin, because his magic is gold. and because merlin is magic, and his magic is so intrinsically unique to him and is unparalleled, it serves to reason that merlin is gold.
the pendragon crest is mostly red-- and, if arthur is red, then camelot is red-- but its dragon, the heart of the crest, is gold.
and, well. if gold is merlin, and merlin is magic, and gold is magic--
there is, after all, magic in the heart of camelot.
