Some of the ITV1 regions on Sky are encrypted, which is why you lost viewing since they updated the viewing cards to the new white ones.The card is also responsible for regionalising your box.
To restore viewing, you can either........
remove the old blue viewing card then reboot your box, i.e switch off at the mains.
When it reboots it will default to an FTA version of ITV- It may not be your current region though.For example,without a card my Sky box defaults to BBC London and ITV Central west (i live in the Tyne Tees North region).
If you're bothered about watching the correct regions, then all the BBC regions appear on the EPG from channel 971 onwards and an FTA version of your ITV region can be added manually and viewed via other channels( if you need help with this just ask).
Or........
The other option is to buy a Freesat from Sky card @ £20 which will regionlise your box, i.e give you your correct BBC/ITV regions on their main 101 and 103 slots on the EPG.
It will also restore viewing for Five, Fiver,Fiver+1,Five USA,Five USA+1, Sky 3 and 4HD(if you have an HD box) which are all encrypted but free channels, which you should of also lost when the old blue card was shut off.
To obtain an FSFS card you need to contact Sky on 08448 244 400.