[PUSHED][PATCH]fdo45671 writer par. bg color simplified code for split button

[Winfried Donkers]

>>> In Excel, the default background colour seems to
>>>be yellow, so let's do something similar here – I don't like yellow
>>>per se, but Excel users are probably used to yellow, so no need to
>>>break the functionality for them.
>>>So, I'd propose to use either "Yellow" or "Chart 3" as the default.
> 
> I did some thinking (some, not a lot) on this matter.
> It seems that the default colour for font and line colour buttons is
> black and for background buttons (highlight excepted) is transparent.
> That does not look usefull to me, is these are bound to be the default
> colours of font, line, background anyway.
> Isn't it a better idea to set the default colours as a contrastong
> colour (eg COL_RED for font/line and COL_YELLOW for background) so that
> users can 'mark' sections without choosing a colour?

To illustrate my suggestion, see attached diff file, which incidently also shows why Astron and Ivan where confused by the gray colour in the background button...
I will fix that with my next split button patch.

Winfried