In re: your search, I'll go into this in more detail when I get around to her World of Wondy post, but Artemis started out as a white chick, with red hair and green eyes, remained so through Byrne, and then was slightly redesigned as more believably Egyptian from circa Luke on up, with her hair sliding more toward auburn than orange, her eyes going more hazel than green, and her skin picking up a bit of yellow/olive color (very little of which improved look has been posted here, I'm afraid). It was an excellent, rational and IMO necessary-for-the-credibility-of-the-franchise change and I'm annoyed by the reversion.
As for why Diana can't possibly currently be a princess:
Nearly Jimenez' first act when he took over the title was to embroil the Bana and the Themyscirans in a stupid and pointless civil war for no legitimate reason, mostly due to the Bana reacting to Polly being the irresponsible useless crapsack he portrayed her as. The Wonders ended this war by abdicating the throne and establishing a democracy, which ended up with Artemis and Phillipus in charge; as of the end of Jimenez' first trade, there is no royalty on Themyscira. Those titles are gone. Hence, why everybody keeps calling Diana "once-princess, once-goddess" and her telling off Io for calling her a princess and Kyle stumbling over what to call her et cetera et cetera. And at no point since have the amazons reinstated the monarchy, which makes sense, why the hell would they? It's not like the tensions that require the shared democratic government are gone, or restructuring a society on that level is a convenient thing to do on a regular basis.
So maybe that storyline got retconned out with ICk, then, okay, and we'll just say it never happened. Except, the problem is, after the monarchy was abolished... Hippolyta died. And we know that that is still canon post-ICk because she was explicitly brought back to life when Shamazons started. And if the monarchy was never abolished, and Hippolyta never died, Diana can't be a princess, she's next in line for succession, she's the fucking Queen. And, incidentally, is also hideously, atrociously, unconscionably irresponsible and covered in fail for continuing to gallivant around Man's World and leaving her people bereft of a leader during the latter half of Jimenez' run and the entirety of Rucka's and 52.
If the second Civil War happened, she can't be a princess, because there is no monarchy. If there is a monarchy, she can't be a princess, because she's the queen.