Selecting an arbitrary color for a data series in LibreOffice Calc chart

I am using LibreOffice I would like to be able to select an arbitrary color (e.g., by RGB value) for the color of a data series. However, I find that I am confined to selecting from a rather limited palette of predetermined colors (cf. included image). How can one select an arbitrary color for a data series?

Note: I was not permitted to upload an image because my reputation (“karma”) is insufficient for this privilege. The image mentioned above is not included but the intent was to show the Data Series dialogue that can be viewed by right-clicking on a data series and selecting “Format Data Series…”.

Hi user001,

It is possible to add new colors with RGB scale to the palette in:

And is possible to add the new color to Chart colors in:
Menu/Tools/Options/Charts/Default colors.