Conditional border color using If( statement

I have a large form with many dropdowns and combo boxes. I have successfully set each (except for a couple) to have a red border if they're blank and a black border if they contain a selection.

The ones I'm having issues with are HourValue and MinuteValue dropdown fields. For all other fields I have been able to use the below code to achieve my goal:

If(

IsBlank(DCV122.Selected) ,

Color.Red,

Color.Black

)

However, when I use the following for my HourValue and MinuteValue dropdown fields, the conditional border color does not work. I don't get an error message, the border just remains black.

If(

IsBlank(HourValue1.Selected), //Note: I have also tried .Selected.Value

Color.Red,

Color.Black

)

I believe the issue is because the field is not truly blank even when no selection has been made. It appears that Date and Time fields from SharePoint lists just create dropdowns that have hard coded choices in the "Items" property--for example, the "Items" property of the HourValue dropdown is ["00","01","02","03"], etc.

So, my question--how can I achieve my desired outcome (red border by default, but black border once a selection has been made) with something other than an If( statement? Or is there a different If( statement I can use? Thank you!