This entirely Enterprise-bound episode is a blatantly obvious take on the issue of racism, no doubt inspired by the Civil Rights movement, which was at its peak in the 1960s when this episode was produced.
In respect of the plot, its concept is rather similar to the many 'moral stories' of the first season (indeed, the story was originally pitched for the first season, then titled "A Portrait in Black And White"). However, being a third season instalment, it is far less subtle, and lacks the classy feel of those earlier episodes.
The Cheron beings, half black and half white, are immediately interesting to look at, and arguably one of the most memorable beings from the Original Series; certainly from later on in the show's run anyway.
However, Kirk and co.'s amazement when the first see Lokai felt slightly wrong; yes he is unusual to look at, but the Enterprise encounters strange new beings and creatures just about every episode; why the particular amazement over Lokai?
Bele is played by Frank Gorshin, probably best known for playing the recurring Riddler in classic 1960s 'Batman', which had ceased production the previous year.
Both Gorshin and Lou Antonio have their moments as the respective Cherons, but these are interspread with some very hammy points.
One thing that did stand out to me was some of the directing – particularly the very dodgy zooming in and out of the red alert lights, which didn't fit with the feel of the episode – or the series in general – at all. In fact, they look like something that would be more at home in the aforementioned '60s 'Batman'!
The racism plot is handled interestingly, but is not perfect. There are some good parallels to problems on Earth during the black slave period, but these points are let down by the plot generally feeling rather forced, and not as focused as it might have been.
Without giving too much away, the conclusion is an interesting and rather bleak one, as there seems to be no real solution to the Cheron's dispute.
All-in-all, this is not a bad episode – there is certainly FAR worse in the third season – and it is well intentioned, but it doesn't have the subtlety or depth that it deserves.