Glad it can be of any use !
Actually I based the palette on the one you can find here :https://www.visibone.com/swatches/
I'm not too skilled in matters of licenses, but as I can see from the above link :
*Usage guidelines: You're more than welcome to download the swatch collections on this page and use them for fun or profit to your heart's content on the same computer on which you downloaded them. Please do not reproduce, derive or distribute without advance permission from VisiBone.
I guess I should then reorder the color order so that it doesn't reproduce the original patterns ...
As for the color codes, I did notice that Synfig keep colors with rounded values, which means colors are slightly differents in the palette file than the html codes inputs. That means
original colors from the visibone swatches for gimp are not the same as in the palette I uploaded. I don't know if I make myself clear...
I'm going to change the palette's pattern, then I'll re-upload it under a license that fits synfig studio's one...
Which one would be fine ?