If you're using the Paletton website to pick colors, then this little add-on can help you transfer them to Blender. It sells for CAD $4.00.
Nicolas Robitaille / NixArt writes:
Hello Blender Community,
I thought this might interest someone. I have made my add-on "Palette Importer" available.
This add-on imports a color palette exported in XML format from Paletton.com. The hue, saturation and value of the imported colors can be offset and the colors can be added to a new palette in Vertex/Texture Paint mode by a simple click. The add-on has been developed in Blender 2.73 and is available on my website.
Thanks!
Nick / NixArt