What can I say, all that pink and purple just seems to be meant to be together.
Credit again to Trek Core for their excellent TAS BlueRay screencap library.
Editing to add: love Barbie, pleased to see the movie out earning most of the comic heroes, always glad that TAS and Prodigy make themselves appealing across genders.
DC Fontana was asking science fiction writers with no prior animated series credits to write an episode of TAS to take advantage of an exceptional provision in the writers contract.
There was a writers strike at the time, and at that time the animated writers were in the same union as live-action. The provision existed to enable writers to move media, and Fontana took full advantage as many TOS writers and science fiction writers had never written for animation.
I haven’t seen specifically that Fontana asked Niven to adapt that specific story, but she and Roddenberry clearly were comfortable with his doing so.