Atualizado para o Connections 5.5

Criando os diretórios

mkdir -p /opt/IBM/SharedArea/customization/themes/hikariTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/gen4Theme
mkdir -p /opt/IBM/SharedArea/customization/themes/pinkTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/redTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/greenTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/onyxTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/goldTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/purpleTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/orangeTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/blueTheme
mkdir -p /opt/IBM/SharedArea/customization/themes/silverTheme

Crie o arquivo custom.css e copie para os demais diretórios

cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/hikariTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/gen4Theme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/pinkTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/redTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/greenTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/onyxTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/goldTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/purpleTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/orangeTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/blueTheme
cp /tmp/custom.css /opt/IBM/SharedArea/customization/themes/silverTheme

Validando

Ao acessar o wiki

1) Criar uma nova Wiki

2) No menu do Editor deve existir a opção