sorry but was trying to create my own palettes today and noticed i couldnt just copy paste my color hexes into any of the color selectors nor specifically adjust their RGB while u know seeing the actual numbers… however you can do all of that from the triangular color selector within the background chooser! it allows you to do all that but only copy the color to the background patterns, not your current palette.
again sorry not sure how hard that would be to make that available as another color selector but it would be nice as i like to use specific colors throughout my art assets.