fix typo in color name

Change-Id: I9dbd6a59b4c0f28d7d5e98767911873135c295ec
Reviewed-on: https://gerrit.libreoffice.org/13070
Reviewed-by: Andras Timar <andras.timar@collabora.com>
Tested-by: Andras Timar <andras.timar@collabora.com>