They may be able to, but you'll still have to pick up the bag when you arrive on the CO flight, take it through customs and re-check it afterwards anyway. This applies to all incoming international flights in the US (with a handful of exceptions)

If you're arriving that late there's a good chance immigration / customs will be quiet, as it's well past the usual afternoon rush. I arrived at 7pm recently and it took just a few minutes to get through.

Overall I think you've got a good chance of getting through on time. And in the absolute worst case, if you turn up late for the VS flight and explain what has happened, there's a very good chance they'll just put you on the next morning's LHR flight - the VS staff at EWR are very good.

Don't forget to do the online checkin though on VS if you're in economy - really does make a difference!