Hi,
Did you ever try to connect with you web browser to https://vca1.vmcolours.com:7444/lookupservice/sdk and check the result ?
Did you check the service status in your appliance admin page (https://vca1.vmcolours.com:5480/) ?
The SSO Service may simply be stopped on your appliance ...
From the appliance, you may also try to check the name solver : does your host can resolve vca1.vmcolours.com with the correct IP ?
Hope it helps.
See you
Ludovic