Web Safe Colours

There is a very limited range of colours considered to be web safe - this doesn't mean these are the only colours you can use but it does mean these are more reliably produced across the technologies used and safest where text and images are used together. Here is a web safe colour chart.

You will see the colours are very limited unlike the millions you have available for print and do not expect to be able to quote a pantone colour and get the equivalent for the web, you can't I am afraid, they are not really compatible, for the web you need the Hex or RGB colour reference.