In addition to the other answers, I’d like to add that colour bleeding was probably a huge factor in these shows looking better on old TVs compared to new one. It’s the same reason why a lot of retro games look bad now, because the way they were designed was for monitors where one pixel would bleed into another, instead of showing as a crisp square.
[Here’s an example of such sprites where modern monitors just don’t do them justice.](https://i.stack.imgur.com/JmOsq.png)
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