Fix color palette for PaperColor themes

[ThomasLamprecht]

Ensure that the palette follows the original, upstream definition [0], as the previous defined ones were quite a bit off. While the colors used are in the PaperColor palette, their place in the palette definition was wrong/scrambled.

I compared the now fixed ones with the VIM variant, which the original PaperColor project defines itself, by simply opening a plain text file there and using cat on the same file in another shell, quickly switching between them to ensure both are rendered the same.

Additionally, I compared the adapted palette here with the PaperColor theme of the foot editor, looks good now.

0: https://github.com/NLKNguyen/papercolor-theme#-colors

E.g., a simple comparison of the papercolor-dark variant:

Previously, with wrong palette:

With this commit and the now original PaperColor palette:

[ThomasLamprecht]

Just checked in on this PR and noticed that the posted screenshots aren't really ideal to show of what/that it's fixed.

So I've redone them with a short shell oneliner to print out the standard palette:
for i in {0..15}; do printf "%2d \e[48;5;${i}m $(printf ' %.0s' {1..50}) \e[0m\n" $i; done

That is much more easily compared with the "Light" column of the original color palette definition:
https://github.com/NLKNguyen/papercolor-theme#-colors

Original:

After applying this PR: