Perhaps you have a bit of old 3 core flex hanging about. You could strip a bit of green and yellow insulation off it, and slide it over the bare earth wire - if it's big enough.
The requirements will allow for a bare earth(CPC) cable to be identified by use of tape, I personally would not and would purchase some green and yellow PVC sleeving.
And the tape is not electric nor an insulator.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local