unwanted rests in Slice

I made a Slice of a measure where I removed rests. When I added the slice to a graphic frame the removed rests reappeared.
I could use a screenshot instead of a Slice, but is there a more kosher way to handle this?

You need to export the slice as color, not mono.

Or you should remove the rests using Edit > Remove Rests so they’re actually removed, rather than hiding them by changing their colour or opacity.

Ooo, that’s interesting! All I know is Edit > Remove Rests. How would I change their colour or opacity?
I don’t know if this would make any difference, but I am doing Edit > Remove Rests via a keyboard shortcut I made for that: Option-R after highlighting the rests.
Oh, I know, maybe this counts too. I like removing all trailing rests from a voice in a measure. I notice that in the Properties Panel, Notes and Rests/“Ends voice” has the effect of removing any and all trailing rests. I know that turning that switch off has the effect of restoring the rest.
I don’t know if all this affects colour or opacity.

The original question, I remind myself, is “What’s the best way to get those removed rests to not reappear for my Slice?”

Edit > Remove Rests does not “hide” the rests or change their opacity: it sets a property on the note or rest before the rest you are asking Dorico to remove that causes the rest not to appear at all. So provided you are using the proper Remove Rests function, it is not possible for such removed rests to reappear when you export graphic slices, regardless of whether you export in mono or colour.