I was able to create a .gpl file colour palette which is working fine with Inkscape. Sadly, the colours auto arranged themselves in some funny order. Probably from
000000. All I had to do was create rectangles of desired hex colours and then save as .gpl using Inkscape. Now that I have placed the .gpl file in the palette folder and restarted Inkscape, all the colours are available when I choose the palette by name, sadly, in a messed up order. It will be great if someone can suggest a fix. Thanks.
I am using Ubuntu 18.04 and whatever the latest Inkscape that comes with it.
Please see the image below for the order in which I have stacked the colours and how it ended up appearing on the palette