Better title for color picker dialog

Also:
* Missing colons stuff (fdo#78826)

Change-Id: I5b4c75d7fc9a2f84d17074e78dbe4875cfdca352
Reviewed-on: https://gerrit.libreoffice.org/11845
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>