Pico-8 pallete loads with repeated colors

[Gortz]

This is the predefined palleted the this software uses
https://i.imgur.com/XYbCsGG.png
This the list of colors in lospec.com
https://lospec.com/palette-list/pico-8

[jan]

This is correct. The standard pico-8 palette in Pro Motion contains the first 16 colors as typical pico colors. Then a range follows where those colors are sorted by perceived brightness. This is useful to select colors for shades from dark to light.

But the Pro Motion pico-8 palette contains even more colors like different smaller ramps useful for stones, plants etc. as vertical or horizontal ramps. This helps to quickly select certain color schemes. pico-8 does not care about indexes when loading an image. It just matches the pixel color to its standard palette, so you can use any of the color slots in the PM pico-palette. Also see the pico-8 project preset description:

...
The color palette is extended by some special color orders and groups to quickly select colors for certain graphic portions like stone, metal, plants etc. .
You can define your own color groups in the palette area, but remember to never change the value of a color. Always use copies from the original color definitions.
PICO-8 will remap every pixel to the standard palette when you load the graphics into it.

For more information see:
https://www.cosmigo.com/promotion/docs/onlinehelp/gfxHardware-PICO8.htm