We should try to use split buttons for all toolbar color choosers, for a longer rationale, see: bug 45671. How to get to see the button: * Open Calc * In the Formatting toolbar, find the Font Color item (icon: an "a" with a colored line below it) See that the button is a simple button, not a split button.
Winfried Donkers committed a patch related to this issue. It has been pushed to "master": http://cgit.freedesktop.org/libreoffice/core/commit/?id=4236f5e19c5d3f3a5007c7a596868d09a7e39bee fdo#45688: Split button for Calc cell font color
Great stuff, Winfried! Thank you!
transparent colour is a choice in the palette, but the cell background does not get transparent. That'll have to be fixed, so I reopened the bug.
fixed under bug 45671
*** Bug 38810 has been marked as a duplicate of this bug. ***