Define custom colors and add them to the Custom color palette.
To define a custom color
Choose Format - Area, click the Area tab and press the Color button. A table of the predefined palette colors is displayed.
Custom colors are saved in the Custom color palette.
Click a color in the table that is similar to the one you want to define. You can select the similar color from any of the available color palettes in the Colors area on the left or the Recent colors in the list below the color table. The color appears in the New preview box to the right of the dialog.
Click the Pick button to open the Pick a Color dialog.
LibreOffice uses only the RGB color model for printing in color. The RGB values of the selected color are displayed below the preview boxes.
Press the Add button to add the custom color to the Custom color palette. A dialog box asking to enter a color name appears. Enter a unique name for the new color within all color names existing in the Custom color palette.
To remove a color from the Custom color palette, select the Custom color palette in the Colors area, select the color to be deleted and click Delete.