Is there a way to highlight selected parts in an assembly?

option 1;

with the filter just showing the "o-ring" parts, drag a box to select them all, and assign a color. then clear the filter.

option 2;

with the filter just showing the "o-ring" parts, drag a box to select them all, and then use "invert selection" to select everything else, and set to transparent. then clear filter.

option 3;

???

I haven't messed with it much, but this looks like something that could be done with Assembly Visualization.

You can sort by any of the columns (or you can add others that refer to custom properties)

This is a quick example sorting by vendor, I wanted to show all of the hardware from one vendor (DMB)

I added the color sliders, so everything above the DMB parts is red, everything below is blue, and all of the DMB parts are white.

todd

one more quick edit - since they are already sorted in the Assembly Visualization tree, it is easy to select parts and change them to transparent -

You can use Component Selection under Tool menu.  I chose the Advanced Select and set Category1 to Custom property and Category2 to Description.  Condition would be contains and the value would be your "o-ring".  This is a good tool to get familiar with.

Not perfect, but how about click the funnel icon (specifically the black triangle) and turn off "Filter Graphics View". Type your search which filters the tree only (graphics remain intact showing parts in context)- use CTRL/SHIFT Select for the items in the tree.