Several dialog boxes in DT show an explanatory text in a smaller grey/gray font, for example here
This is perhaps done with an Apple UI framework. Even so, the contrast of the text (measured with WebAIM: Contrast Checker) is 1.8:1, which is ridiculously low. If that were a dialog on the web, it would fail a basic accessibility check, as the contrast should be at least (!) 4.5:1.
To achieve that, the explanatory text should be shown a lot darker, in hex color #696969 instead of #b4b4b4. Here’s how that looks in another app, which probably uses simply black as the font color:
Alternatively, a question mark icon besides the option could be used to save real screen estate. If the user clicks on it, they could then be shown the explanation in normal text inside a popup. That’s what the “MoneyMoney” banking app does (see below).
