In Dutch I can let the user choose between (a software setting):

Alleen indien NIET toegestaan
Alleen indien WEL toegestaan

for which I think the English translation should be:

Only when NOT allowed
Only when allowed

But as you can see, that translation misses the visual emphasis (capitals) for the positive choice.
Is there something I can do with the translation that would let me use emphasis for both choices?

In Dutch I can let the user choose between (a software setting):

Alleen indien NIET toegestaan
Alleen indien WEL toegestaan

for which I think the English translation should be:

Only when NOT allowed
Only when allowed

But as you can see, that translation misses the visual emphasis (capitals) for the positive choice.
Is there something I can do with the translation that would let me use emphasis for both choices?

Notes:

1. This is a configuration setting with a 3rd choice: N/a

2. I do not have the option of making this (much) longer like in

Only when overtime is NOT allowed
Only when overtime IS allowed

That is exactly the issue, it seems: there is no noun to refer to.