Homer Simpson writes:
As of only a few years ago, it was possible to have a
traditional deductible account in a 401(k) or 403b but
now also non-deductible Roth accounts in 401(k)s, too.
So not only are there 401(k)s, but there are also Roth 401(k)s.
No such amendment was made to 457s. There are no Roth 457s.
None of this has any bearing on your ability to have a Roth IRA.
It's entirely separate.
So, yes, assuming you're otherwise eligible to make Roth IRA
contributions (ie. your income is below the limit), you may
make both a Roth IRA contribution as well as your 457