Combobox Greyed Out Items

Hi,

Is it possible to create a list of items that show for example:

Clickable items: Black - Bold Font
Non-Clickable Items: Grey - Regular Font

Example:

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COMBOBOX TITLE v
-----------------------
Item 1
Item 2
Item 3
Item 4
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Where items 1 and 4 are selectable (clickable) and items 2 and 3 non clickables (no hand cursor - no links)

Thanks!!