alt Hacker NewsThe C64 palette is completely different from the EGA palette.
C64: https://lospec.com/palette-list/commodore64
Default EGA palette (which Afaik monkey island used): https://lospec.com/palette-list/color-graphics-adapter
You see that the C64 palette has a much more muted, pastel look and does not map one to one to the CGA/default EGA palette. C64 has a lot less vivid colors, but it also has much better luminosity ramps which can make dithering look a lot better.
In addition, the C64 has restrictions on the number of colors you can use in the same 8x8 block which I don't think EGA had.
It takes an artist to turn a CGA/EGA image into a C64 image.
I think the C64 palette you linked has been "tweaked" by the artist who uploaded it, this is probably closer to the original: https://www.c64-wiki.com/wiki/Color
But your point is still valid: while IBM PCs and other machines of the time had a propensity for "pure" colors (cyan, magenta etc. - so 100% for one or two of the basic colors and 0 for the others), the C64 designers opted for more muted colors.